### Home > A2C > Chapter 7 > Lesson 7.3.5 > Problem7-219

7-219.

Use matrices to solve these systems. Check your answers by substituting them in the original equations. You will not need a calculator if you use the results of the previous problem.

1. $p + 2q = 7 \\3p + 4q = 11$

First substitute matrices for the equations.

Multiply both sides by the inverse.

Solve for p and q.

1. $4m − 5n = −2 \\−3m + 4n = 9$

See part (a).