PSAT Math Multiple-Choice Practice Question 550

Correct Answer: B

Explanation:

(B) You can use substitution to solve, although elimination could also work.

3x + y = -3

x - 2y = -8

Rearrange the second equation to be in terms of y:

x - 2y = -8

x = 2y - 8

Substitute into the first equation and solve for y:

3x + y = -3

3(2y - 8) + y = -3

6y - 24 + y = -3

7y - 24 = -3

7y = 21

y = 3

Then plug in 3 for y into the first equation to solve for x:

3x + y = -3

3x + 3 = -3

3x = -6

x = -2