Question

2x+y= 3

x-2y= -1
If equation two is multiplied by -2, and then the equations are added, the result is

Answer 1

5y = 5

Explanation:

When the second equation is multiplied by -2, it becomes ...

-2(x -2y) = -2(-1)

-2x +4y = 2

Adding this to the first equation gives ...

(2x +y) +(-2x +4y) = (3) +(2)

2x +y -2x +4y = 5 . . . . . . . . . eliminate parentheses

5y = 5 . . . . . . . . . . . . . . . . . . .collect terms