Question

What is the value of x in the solution to this system of equations?

5x - 5y = 120
y = -7x + 8
Enter your answer in the box.
X = what is x?!?!

Answer 1

{x = 4

{y = -20

Explanation:

{5x - 5y = 120

{y = -7x + 8

5x - 5(-7x +8) = 120

5x + 35x - 40 = 120

40x - 40 = 120

40x = 120 + 40

40x = 160

x = 160/40

(cross out common factor)

x = 4

-----------

x = 4 (next is y)

y = -7 x 4 + 8 (calculate)

y = 20

y = -20

solution of system;

{x = 4

{y = 20