Question

Y=-3x-7 y=x+9 solve by substitution how do I do this, I'm so lost!

Answer 1

x=-4, y=5

Explanation:

Because y=-3x-7 and y=x+9, so y=y, and -3x-7=x+9

-3x-7=x+9,

so 4x=-16

x=-4

so we put x=-4 to y=-3x-7

y=(-3)* (-4)-7

y=12-7

y=5

Answer 2

Solve for the first variable in one of the equations, then substitute the result into the other equation.

Answer:

Point Form:

(−8,−17)

Equation Form: x=−8,y=−17