Question

How do you solve the system `x+2y=5` and `5x-y=3`?

Answer 1

From the first equation we learn that
`x=5-2y`

If we substitute that value for `x` in the second equation:
`5*(5-2y)-y=3->`
`25-10y-y=3->` subtract 3
`22-11y=0->22=11y->y=2`
Back to the first equation:
`x=5-2*2=1`

Check the answer:
`1+2*2=5and5*1-2=3`