Question

Solve the system by substitution. y = 3x + 28 y=-4x

Answer 1

Step-by-step explanation:

Substituting y = - 4x then putting in the equation

-4x = 3x + 28

Bringing like terms on one side

-4x - 3x = 28

-7x = 28

- ( 7x = - 28

x = - 28 / 7 = - 4

Answer 2

Answer:

(-4, 16)

Step-by-step explanation:

Since y = -4x, substitute -4x for y in the first equation:

-4x = 3x + 28, or

-7x = 28.  Then x must be -4.

According to the second equation, y = -4x.  Thus, if x = -4, y = -4(-4) = +16.

The solution is (-4, 16).