Question

If you were to solve the following system by substitution, what would be the best variable to solve for and from what equation?​

Answer 1

Answer: y would be good for the second equation.

Explanation:

2x + 8y = 12

(2x + 8y) + (-8) = 12 + (-8y)

2x + 8y - 8y = 12 - 8y

2x = -8y + 12

2x/2 = -8y + 12/2

X = -2^3 x y + 2^2 x 3/2

X = 2^2(-2^3 x y/2^2 + 2^2 x 3 /2^2)/2

X = 2^2 (-(2^3 - 2 x y) + 3)/2

X = 2^2 (-(2y) + 3)/2

X = 2^2 - 1 (-2y + 3)

X = 2 (-2y + 3)

X = -2 x 2y + 2 x 3

X = -4y + 6

3x - 8y = 11

(3x + 8y) + (-3x) = 11 + (-3x)

3x + 8y - 3x = 11 - 3x

Y = -3x + 11/8

It looks like y would be good for the second equation.

Answer 2

on apex, it is "x, in the first equation" :)

Explanation:

The second equation does not have coefficients that easily divide. In the first equation, if you were to solve y, you would end up with fractions in your coefficients. Solving for x produces integer coefficients.