Question

Y=x-15 y=-4x slove the sytem by subsitution.If there is one solution,express it as an order pair. no solution,infintie number of solution, if there is a solution explain it in () form

Answer 1

(3,-12)

x = 3, y = -12

Explanation:

(1) y=x-15

(2) y=-4x

solve equation (1) for x:

add 15 to both sides

x=y+15

plug in x=y+15 into equation (2):

y=-4(y+15)

y=-4y - 60

5y = -60

y = -12

plug in y=-12 into equation (2):

-12 = -4x

3 = x