Question

What is the solution of the system of equations?

y = x - 10

y = 2x + 5

Answer 1

x = -15 and y = -25 ⇒ (-15, -25)

Explanation:

`y=x-10\qquad(1)\\\\y=2x+5\qquad(2)\\\\\text{substitute (2) to (1):}\\\\2x+5=x-10\qquad\text{subtract 5 from both sides}\\\\2x=x-15\qquad\text{subtract x from both sides}\\\\x=-15\\\\\text{Put the value of x to (1):}\\\\y=-15-10\\\\y=-25`