381,718 views
7 votes
7 votes
Solve using substitution.5x + 4y = -12x = -8

User Thebat
by
3.2k points

1 Answer

13 votes
13 votes

Let:


\begin{gathered} 5x+4y=-12_{\text{ }}(1) \\ x=-8_{\text{ }}(2) \end{gathered}

Replace (2) into (1):


\begin{gathered} 5(-8)+4y=-12 \\ -40+4y=-12 \\ solve_{\text{ }}for_{\text{ }}y\colon \\ 4y=40-12 \\ 4y=28 \\ y=(28)/(4) \\ y=7 \end{gathered}

So:

x = -8

y = 7

User Andrea Salicetti
by
2.7k points