ASVAB Mathematics Knowledge Practice: Solving for Variables

The Mathematics Knowledge subtest on the ASVAB contains a lot of questions where you're asked to solve for a variable in an algebraic equation. The best way to do this is to isolate that variable.

Practice questions

1. Solve for x: 4x + 6 = –30

   A. –8 B. 4 C. –9 D. 9

2. Solve for x: –10x + –23 = 23 + –8x
   A. –22 B. 23 C. –23 D. –24

Answers and explanations

1. The correct answer is Choice (C).

   Isolate x:

   

2. The correct answer is Choice (C).

   Put the variables on the same side of the equation:

   

   Isolate x by dividing both sides of the equation by –2: