# How do you solve for x and y in 2x + y = 3 and x - 3y = 12?

I wouls isolate $y$ from the first equation:
$y = 3 - 2 x$
$x - 3 \left(3 - 2 x\right) = 12$
and solve for $x$:
$x - 9 + 6 x = 12$
$x = 3$
So that going back to: $y = 3 - 2 x$
$y = 3 - 6 = - 3$