Answer:
A.
3x + 3y = 0
7x − y = 8
Step-by-step explanation:
Given
3x + 3y = 0
-4x + 4y = -8
Required
Find the equivalent
To solve for the equivalent we simply solve for x and y in the given equation.
Subtract 3x from both sides in 3x + 3y = 0
3x - 3x + 3y = 0 - 3x
3y = -3x
Multiply both sides by ⅓
⅓ * 3y = -3x * ⅓
y = -x
Substitute -x for y in -4x + 4y = -8
-4x + 4(-x) = -8
-4x -4x = -8
-8x = -8
Multiply both sides by -⅛
-⅛ * -8x = -⅛ * -8
x = 1
Recall that y = -x
y = -1
So, we have that x = 1 and y = -1
We'll substitute these values in the list of options;
A.
3x + 3y = 0
7x − y = 8
7(1) - -(1) = 8
7 + 1 = 8 ----- This is equivalent
B.
3x + 3y = 0
−7x − y = 8
-7(1) - (-1) = 8
-7 + 1 = 8
-6 ≠ 8 .... This is not an equivalent expression
C.
3x + 3y = 0
−7x + 7y = 8
-7(1) + 7(-1) = 8
-7 -7 = 8
-14 ≠ 8 .... This is also not an equivalent expression
D.
3x + 3y = 0
-4x + 7y = 8
-4(1) + 7(-1) = 8
-4 -7 = 8
-11 ≠ 8 -_- This is also not an equivalent expression
