Answer:
The answer is c
Step-by-step explanation:
Exercise 2.4.2: Proving statements about rational numbers with direct proofs. About Prove each of the following statements using a direct proof. (a) The product of two rational numbers is a rational number. Solution (b) The quotient of a rational number and a non-zero rational number is a rational number. Solution (c) If x and y are rational numbers then is also a rational number.
Answer:
See Explanation
Step-by-step explanation:
(a) Proof: Product of two rational numbers
Using direct proofs.
Let the two rational numbers be A and B.
Such that:
[tex]A = \frac{1}{2}[/tex]
[tex]B = \frac{2}{3}[/tex]
The product:
[tex]A * B = \frac{1}{2} * \frac{2}{3}[/tex]
[tex]A * B = \frac{1}{1} * \frac{1}{3}[/tex]
[tex]A * B = 1 * \frac{1}{3}[/tex]
[tex]A * B = \frac{1}{3}[/tex]
Proved, because 1/3 is rational
(b) Proof: Quotient of a rational number and a non-zero rational number
Using direct proofs.
Let the two rational numbers be A and B.
Such that:
[tex]A = \frac{1}{2}[/tex]
[tex]B = \frac{2}{3}[/tex]
The quotient:
[tex]A / B = \frac{1}{2} / \frac{2}{3}[/tex]
Express as product
[tex]A / B = \frac{1}{2} / \frac{3}{2}[/tex]
[tex]A / B = \frac{1*3}{2*2}[/tex]
[tex]A / B = \frac{3}{4}[/tex]
Proved, because 3/4 is rational
(c) x + y is rational (missing from the question)
Using direct proofs.
Let x and y be
Such that:
[tex]x = \frac{1}{2}[/tex]
[tex]y = \frac{2}{3}[/tex]
The sum:
[tex]x + y = \frac{1}{2} + \frac{2}{3}[/tex]
Take LCM
[tex]x + y = \frac{3+4}{6}[/tex]
[tex]x + y = \frac{7}{6}[/tex]
Proved, because 7/6 is rational
The above proof works for all values of A, B, x and y; as long as they are rational values
find the value of n the equation 1/2(n+4)=6
Answer:
n = 8
Step-by-step explanation:
1/2(n + 4) = 6
1/2 of n + 2 = 6
6 - 2 = 4
4 × 2 = 8
1/2 of 8 + 2 = 6
4 + 2 = 6
n = 8
E=mc squared m=3 c=6
Answer:
E = 108
Step-by-step explanation:
E = 3 * [tex]6^{2}[/tex]
= 108
Answer:
e=mc^2 if m=3 and c=6
e=3([tex]6^2[/tex])
e=3[tex](36)[/tex]
e=108
Step-by-step explanation:
hope this helps have a good rest of your day/afternoon :) ❤
13,406,109 pennis into dollars
Answer:
$134,061.09
Step-by-step explanation:
hope this helps
Answer:
134,061.09
Step-by-step explanation:
Divide 13,409,109 by 100
$134,061.09This can also be expressed as 134, 061 dollars, and 9 pennies.
The membership fee at a sports club was $600 per year. Each year, the membership fee increased by 7%.
Which equation models the cost of the membership fee, y, after 2 years?
Answer:
600(1.07)^2=y
Step-by-step explanation:
Find the area of the figure
Answer:
Step-by-step explanation:
Just add it
Formula for parallelogram law of addition
Answer:
answers?
Step-by-step explanation:
Find the midpoint of A and B where A has coordinates (8,5)
and B has coordinates (3, 7).
Answer:
Step-by-step explanation:
Average of x-coordinates = (8+3)/2 = 5.5
Average of y-coordinates = (5+7)/2 = 6
Midpoint at (5.5,6)
Find the volume of the cylinder and cone, then add them together.
★ Volume of cylinder :-
V = πr²hHere,
r is radius h is heightWe have :
r = 2cm h = 7cmSubstituting the values :
> V = π (2 × 2) × 7
> V = 4π × 7
> V = 28π
★ Volume of cone :-
V = ⅓ π²hWe have :
r = 2cm h = 6 cmSubstituting the values :
> V = ⅓ × π × (2 × 2) × 6
> V = ⅓ × π × 4 × 6
> V = ⅓ × π × 24
> V = 8π
★ According to the question :-
Adding them together,
> Total Volume = 8π + 28π
> Total Volume = 36π
[tex]Total \: \: \: Volume = (88+176) {cm}^{2} \\ \\ = 264 {cm}^{2} .[/tex]
There are 15 students on the chess team. Seven of the students are in the fourth grade.
Which shows the fraction of the team that is in the fourth grade?
A.
4
5
B.
7
15
O
C
8
15
OD. 15
7
Answer:
7/15 (B)
Step-by-step explanation:
7 fourth graders out of 15 total = 7/15
Leon’s older brother is 4 3/4 feet tall Leon is a 1/3 foot shorter than his brother how. tall is Leon?
Answer:
Leon is 4 5/12
Step-by-step explanation:
4 3/4 - 1/3 change 4 4/12 - 4/12 = 4 5/12
♂️♂️♂️help me plz I dont no 1+1
Answer:
The answer is 2
Step-by-step explanation:
Since the number 1 plus 1 is 2
What is the perimeter of a rectangle with two lentghs of 5
Answer:
20
Step-by-step explanation:
in perimeter you have to add all the sides but rectabgless all have the same size so 5 x 4 since rectangle has 4 sides equls 20 so 20 is the answer
If a watch costs $40 and you must pay 6.5 % sales tax, how much will the tax be?
Please give me the correct answer this is for a test and im on a time limit :(
Answer:
$2.60
Step-by-step explanation:
40 x 0.065 = $2.60
Answer:
the tax would be 2.60$
Step-by-step explanation:
6.5% of 40 is 2.6
(6.5 x .40=2.6)
I need help with this
Which line has a slope of -1/2?
f (x) = 5x -3 what is f (5) =
Answer:
22is answer
f (x) = 5x -3
f (5) =5×5-3=25-3=22
Answer:
5
Step-by-step explanation:
f(x)=5x−3
The derivative of a polynomial is the sum of the derivatives of its terms. The derivative of a constant term is 0. The derivative of ax^n is nax^n−1 .
5x^1−1
Subtract 1 from 1.
5x^0
For any term t except 0, t^0 =1.
5×1
For any term t, t×1=t and 1t=t.
5
A large rectangular movie screen in an IMAX theater has an area of 7,875 square feet. Find the dimensions of the screen if it is 30 feet longer than it is wide.
Answer:
Width=75
length=105
Step-by-step explanation:
Width=x
length=30+x
= 7875=x*30+x
x^2+30x-7875=0
x^2+105x-75x-7875=0
x(x+105)-75(x+105)=0
Find the length of side x in simplest radical form with a rational denominator
Answer:
[tex] x = \sqrt{2} [/tex]
Step-by-step explanation:
[tex] \tan 30 \degree = \frac{x}{ \sqrt{6} } \\ \\ \frac{1}{ \sqrt{3} } = \frac{x}{ \sqrt{6} } \\ \\ x = \frac{ \sqrt{6} }{ \sqrt{3} } \\ \\ x = \frac{ \: \sqrt{3} \times \sqrt{2} }{ \sqrt{3} } \\ \\ x = \sqrt{2} [/tex]
Find the measure of CD.
mCD= [?] degrees
Given:
A circle with radius 7 units and chord CD = 7 units.
To find:
The measure of arc CD.
Solution:
Let O be the center of the circle.
In triangle OCD,
[tex]OC=7[/tex] (Given)
[tex]OC=OD=7[/tex] (Radii of same circle)
[tex]CD=7[/tex] (Given)
Since [tex]OC=CD=OD[/tex] all sides are equal, therefore, the triangle OCD is an equilateral triangle.
Measure of each angle of an equilateral triangle is 60 degrees. So,
[tex]m\angle COD=60^\circ[/tex]
The measure of central angle is equal to the measure of corresponding arc.
[tex]m(arcCD)=m\angle COD[/tex]
[tex]m(arcCD)=60^\circ[/tex]
Therefore, the measure of arc CD is 60 degrees.
The area of a circle is 100π ft². What is the circumference, in feet? Express your answer in terms of π.
Answer:
Answer: 20pi is the circumference
Step-by-step explanation:
The circumference of the circle is 20π ft when the area of the circle is 100π ft².
What is circle?A circle is a locus of the points drawn at an equidistant from a fixed point. The fixed point is called Centre of the circle and the distance from the fixed point to the circle is called radius.
Given, area of a circle is 100π.
Therefore, πr² =100π, where r is the radius of the circle.
So, r²=100
Thus, r= 10 ft.
now, circumference = 2πr
=2π×10
=20π ft.
To learn more about circle click here:
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How many 1/3 are in 2 3/4?
Answer: For example, in order to explain why 1/3 + 1/4 = 7/12, we considered the task of dividing 7 apples between 12 boys under the restriction that an apple ... How many halves are in the whole? ... 1 = 3 × 1/3, 2 = 6 × 1/3, 3 = 9 × 1/3, 4 = 12 × 1/3.
Step-by-step explanation:
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PLEASE HELP GEOMETRY
Answer:
Step-by-step explanation:
Triangle R Q S is cut by line segment T V. Line segment T V goes from side Q R to side R S. The length of R V is x + 10, the length of V S is x, the length of R T is x + 4, and the length of T Q is x minus 3. Which value of x would make Line segment T V is parallel to Line segment Q S?
PLEASE HURRY
9514 1404 393
Answer:
x = 10
Step-by-step explanation:
In order for TV to be parallel to QS, it must divide the sides of the triangle proportionally.
RT/TQ = RV/VS
(x+4)/(x-3) = (x+10)/(x)
1 +7/(x-3) = 1 +10/x . . . . expand each fraction
7/(x -3) = 10/x . . . . . . . . subtract 1
7x = 10(x -3) . . . . . . . . . cross multiply
30 = 3x . . . . . . . . . . . . add 30-7x, simplify
10 = x . . . . . . . . . . . . . . divide by 3
The value of x that makes the segments parallel is 10.
_____
Alternate solution
You can cross multiply the first fraction we wrote to get ...
x(x +4) = (x -3)(x +10)
x^2 +4x = x^2 +7x -30 . . . eliminate parentheses
30 = 3x . . . . . . subtract x^2+4x-30 from both sides
Answer: C. 10
Step-by-step explanation:
i got it right on the test
What is the product?
213 × 314
Answer:
66882
Step-by-step explanation:
Answer:
product
Step-by-step explanation:
213×314=66,882
5x-11=24
????????????
Answer:
x= 7
Step-by-step explanation:
5x-11=24
+11 +11
5x = 35 35/5 = 7 x=7
5(7) - 11 = 24
35 - 11 = 24
Answer:
x=7
Step-by-step explanation:
5x7= 35
35-11=24
5x7-11=24
hope this helps!!!
Can someone help me find the distance between the points (-5,3) and (-4,2)
Answer: 1.4142
Step-by-step explanation:
Input Data :Point 1 (xA,yA) = (-5, 3) Point 2(xb,yB) = (-4, 2)
Objective : Find the distance between two given points on a line?
Formula :Distance between two points = √(xB-xA)^2+(yB−yA)^2
Solution :
Distance between two points = √(−4−−5)2+(2−3)2= √12+(−1)2= √1+1= √2 = 1.4142
Distance between points (-5, 3) and (-4, 2) is 1.4142
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An object that weighs 18 pounds on Mercury weighs approximately 60 pounds on Earth. A rock weighs 120 pounds on Mercury. What is the approximate weight of the rock, in pounds, on Earth
Answer: 400
Step-by-step explanation:
I'm not sure 400
In one building, an elevator takes 15 seconds to go up 5 floors.
In another building, an elevator goes up for 60 seconds at the
same rate. How many floors did the elevator in the second
building travel?
Answer:
20 floors
Step-by-step explanation:
15 sec to go up 5 floors is climbing one floor every 3 seconds
3 sec x 20 = 60 seconds
1 fl x 20 = 20 floors
Find the slope of the line passing through the points (-2,-3) and (2,5) 
Answer:
Undefined
Step-by-step explanation: