Question

Consider the following pair of equations:y = -2x + 8y = x - 1Explain how you will solve the pair of equations by substitution. Show all the steps and write the solution in (x, y) form.

Answer 1

We have the next system of equations

$\begin{gathered} y=-2x+8 \\ y=x-1 \end{gathered}$

we will substitute the first equation in the second equation

$-2x+8=x-1$

then we sum similar terms

$\begin{gathered} -2x-x=-1-8 \\ -3x=-9 \\ x=\frac{-9}{-3} \\ x=3 \end{gathered}$

then we substitute the value of x in the second equation

y=3-1

y=2

The solution is (3,2)