<u>Answer</u>:
x = 7, y = 2
<u>Explanation</u>:
equations given:
x + 7y = 21
x + 4y = 15
make "x" the subject:
x + 7y = 21
x = 21 - 7y .........equation 1
x + 4y = 15
x = 15 - 4y .......equation 2
Solving both the equations simultaneously:
15 - 4y = 21 - 7y
-4y + 7y = 21 - 15
3y = 6
y = 6 ÷ 3
y = 2
If y is 2
Then x = 21 -7y;
x = 21 - 7(2)
x = 21 - 14
x = 7
Answer:
c
Step-by-step explanation:
A cube is a 3 dimensional object with 6 square faces. All its sides are the same length, there fore the volume is equal to

where s is the side length.

To solve for s, take the cube root of both sides.
![\sqrt[3]{s^3}= \sqrt[3]{ \frac{27}{64} }](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7Bs%5E3%7D%3D%20%5Csqrt%5B3%5D%7B%20%5Cfrac%7B27%7D%7B64%7D%20%7D%20%20)

feet
x = 4 and EF = 4 ⇒ 3rd answer
Step-by-step explanation:
If two triangles are congruent, then
1. Their corresponding sides are equal
2. Their corresponding angles are equal
3. Their areas and perimeters are equal
∵ △ ABC ≅ △ DEF
∴ AB ≅ DE
∴ BC ≅ EF
∴ AC ≅ DF
∵ BC = 4 x - 12
∵ EF = -3 x + 16
∵ BC = EF
∴ 4 x - 12 = -3 x + 16
Let us solve the equation to find x
∵ 4 x - 12 = -3 x + 16
- Add 3 x for both sides
∴ 7 x - 12 = 16
- Add 12 to both sides
∴ 7 x = 28
- Divide both sides by 7
∴ x = 4
Substitute the value of x in the expression of EF
∵ EF = -3 x + 16
∵ x = 4
∴ EF = -3(4) + 16 = -12 + 16
∴ EF = 4
x = 4 and EF = 4
Learn more:
You can learn more about congruence of Δs in brainly.com/question/3202836
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