Question

Solve the following system by using elemination -2x-5y=-15 x+ 8y=13

Answer 1

-2x-5y=-15

x+8y=13

by multiplying the 2nd equation by 2 :

2(x+8y)=13)--->2x+16y=26

-2x-5y=-15

2x+16y=26

--->11y=11

y =1

we calculate x :

-2x-5y=-15

-2x-5=-15

-2x=-15+10

x=5/2 = 2.5

solution {2.5, 1}