PSAT/NMSQT Prep 2022 - Eggert M.D., Strelka A. 2022

On test day
Systems of linear equations
The heart of algebra

Many PSAT Math questions can be solved in more than one way. A little efficiency goes a long way in helping you get through the Math sections on time, so it’s useful to try solving problems more than one way to learn which way is fastest.

Try this question using two approaches: substitution and combination. Time yourself on each attempt. Which approach allowed you to get to the answer faster?

16. What is the value of x if 25x − 7y = 28 and 10x + 7y + 18 = 60?

A.

B.

C.2

D.

The answer and both ways of solving can be found at the end of this chapter.