Question

Solve the System -5r - 4s - 6t = -6, 4r - 2s - t = -23, and 5r - 2s + 4t = -12?

Answer 1

Step 1:

Elimination method.

The system of equations are

Use the elimination method to make a system of two equations in two variables.

To eliminate the variable, subtract equation (3) from (2).

Multiply on each side of the equation (2) by 2.

To eliminate the variable, subtract  equation (5) from equation (1).

Multiply on each side of the equation (4) by 13.

To eliminate the variable, subtract equation (6) from (7).

.

Step 2:

Substitute in equation (4).

.

Substitute and in equation (2).

.

, and .

Solution:

, and .