Question

What is the solution to the system of equations?

Use the substitution method to solve.

6=−4x+y−5x−y=21

Enter your answer in the boxes.

Answer 1

(x, y) = (-3, -6)

Explanation:

The second equation can be used to write an expression for y:

... -5x -21 = y . . . . . . . add y-21 to both sides

This expression can be substituted for y in the first equation:

... 6 = -4x +(-5x -21)

... 27 = -9x . . . . . add 21, collect terms

... -3 = x . . . . . . . divide by -9

Using this value of x in the expression for y, we find ...

... -5(-3) -21 = y = -6

The solution is x = -3, y = -6.