How to solve 5x-y=-5 and 3x-6y=24 algebraically
\(\displaystyle\\ 5x-y=-5~~~\Longrightarrow~~~\boxed{y = 5x+5} \\ 3x-6y=24 \\ \cdots \\ 3x - 6(5x+5) = 24\\ 3x-30x-30=24 \\ 3x-30x=24+30 \\ -27x = 54\\\\ x = - \frac{54}{27} = \boxed{-2} \\\\ y = 5x+5 = 5\cdot (-2) + 5 =-10+5 = \boxed{-5}\)
