What is the solution to the system of equations? Use the substitution meathod to solve. 6=-4x+y and - 5x-y=21

(-3,-6)

Step-by-step explanation:

A system of equations is 2 or more equations for which the same x, y solution exists. We can solve the system in three ways: elimination, substitution, or graphing. Substitution can be used by substituting the value of one variable into the equation.

We can solve for y in 6=-4x+y. 6+4x=y.

Because y=6+4x, we can substitute 6+4x into y in - 5x-y=21.

-5x-y=21

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

-5x-6-4x=21

-9x-6=21

-9x=27

x=-3

We now substitute x=-3 into y=6+4x.

y=6+4x

y=6+4 (-3)

y=6-12

y=-6