Question

Consider the following pair of equations:y = 3x + 3y = 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

Given:

`\begin{gathered} y=3x+3 \\ \\ y=x-1 \end{gathered}`

Find: the value (x,y)

Sol:

`\begin{gathered} y=3x+3 \\ \\ y=x-1 \end{gathered}`

Substitute the value of "y" in another equation than:

`\begin{gathered} x-1=3x+3 \\ \\ 3x-x=-3-1 \\ \\ 2x=-4 \\ \\ x=(-4)/(2) \\ \\ x=-2 \end{gathered}`

Put the value in the above equation.

`\begin{gathered} y=x-1 \\ \\ x=-2 \\ \\ y=(-2)-1 \\ \\ y=-3 \end{gathered}`

So,

`\text{ The value is \lparen-2,-3\rparen}`