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Solve the system of equations below. You may want to use the method by substitution starting with the second equation.

Solve the system of equations below. You may want to use the method by substitution-example-1
User Questieme
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1 Answer

16 votes
16 votes

Given

The system of equation,


\begin{gathered} 3x-2y=42 \\ 5x+10y=-10 \end{gathered}

To find:

The solution to the system of equation.

Step-by-step explanation:

It is given that,


\begin{gathered} 3x-2y=42 \\ 5x+10y=-10 \end{gathered}

That implies,

From the second equation,


\begin{gathered} 5x+10y=-10 \\ /5\Rightarrow x+2y=-2 \\ \Rightarrow x=-2y-2 \end{gathered}

Substitute x in the first equaton,


\begin{gathered} 3(-2-2y)-2y=42 \\ -6-6y-2y=42 \\ -8y=42+6 \\ -8y=48 \\ y=(48)/(-8) \\ y=-6 \end{gathered}

Therefore,


\begin{gathered} x=-2(-6)-2 \\ x=12-2 \\ x=10 \end{gathered}

Hence, the solution is (10,-6).

User Max Barrass
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2.7k points