Question

For the following system, if you isolated x in the second equation to use the Substitution Method, what expression would you substitute into the first equation?

2x + y = 8
−x − 3y = −12

A) 3y + 12
B) -3y + 12
C) 3y - 12
D) -3y - 12

Answer 1

To solve the system using the Substitution Method, you would isolate x in the second equation to get x = 3y + 12, option A) 3y + 12. This would then be substituted into the first equation.

Step-by-step explanation:

To use the Substitution Method for solving the given system of equations, you first isolate x in the second equation, which is −x − 3y = −12. To isolate x, you would add 3y and 12 to both sides, yielding x = 3y + 12. This expression is then substituted into the first equation, 2x + y = 8, in place of x. So the correct expression to substitute into the first equation is A) 3y + 12.