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Solve the system of equations using the substitution method. show all work

Solve the system of equations using the substitution method. show all work-example-1
User Loman
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1 Answer

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We have the system of equations:


\begin{gathered} 4x-y=7 \\ 5x-8y=2 \end{gathered}

As we will solve it by substitution, the easiest way is to clear y from the first equation:


\begin{gathered} 4x-y=7 \\ 4x-7=y \\ y=4x-7 \end{gathered}

Then, we replace y in the second equation and solve for x:


\begin{gathered} 5x-8y=2 \\ 5x-8(4x-7)=2 \\ 5x-32x+56=2 \\ -27x=2-56 \\ -27x=-54 \\ x=(-54)/(-27) \\ x=2 \end{gathered}

Now, we solve for y as:


y=4x-7=4\cdot2-7=8-7=1

Answer: x=2 and y=1.

User Avram Tudor
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