256,961 views
7 votes
7 votes
Use substitution in the system of equations. What is the value of x in both equations?A. 3B. -6C. 6D. 2

Use substitution in the system of equations. What is the value of x in both equations-example-1
User Shekhar Pande
by
2.9k points

1 Answer

28 votes
28 votes

Given the following question:


\begin{gathered} 3x+2y=-12 \\ x=4y-18 \end{gathered}
\begin{gathered} 3x+2y=-12 \\ x=4y-18 \\ \text{ Substitute x=4y - 18 into the first equation:} \\ 3(4y-18)+2y=-12 \\ 18-4=14y \\ 14y-54=-12 \\ -12+54=42 \\ y=3 \\ \text{ Substitute to find x} \\ x=4*3-18 \\ 4*3=12 \\ 12-18=-6 \\ x=-6,y=3 \\ x=-6 \end{gathered}

Option B is your answer.

User Elsa Li
by
2.7k points