Question

How do you solve `8x+5y=184`, `x-y=3` using substitution?

Answer 1

`(x,y) in {(199/13, 160/13)} subset QQ times QQ`

Explanation:

The second equation have coefficients 1 and -1. Do you want an equation in x? Isolate y.
`x - 3 = y`
From the first,
`8x + 5(x - 3) = 184`
`8x + 5x - 15 = 184`
`13x = 184 + 15`
`x = 199/13`
`y = x - 3 = 199/13 - 3 = 160/13`