Question

Simultaneous equasions x + 2y = 9 and 3x + y = 2

Answer 1

x=-1 y=5

Explanation:

x+2y=9

3x+y=2

If we multiply the second equation by -2 we get

-6x-2y=-4

then if we add this to x+2y=9 we get

-5x=5

if we multiply both sides by -1 we get

5x=-5

divide both sides by 5 we get

x=-1

multiplying the first equation by -3 we get

-3x-6y=-27

adding this to the original second equation we get

-5y=-25

multiply both sides by -1

5y=25

divide both sides by 5

y=5