Question

What is the solution of the system of equation below y=x-4y=3x

Answer 1

`\mleft\{\begin{aligned}y=x-4 \\ y=3x\end{aligned}\mright.`

Replace one of the equations into the other leaving only x as a variable

`3x=x-4`

solve the equation for x

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

replace the x into one of the first two equations

`\begin{gathered} y=(x)-4 \\ y=-2-4 \\ y=-6 \end{gathered}`

the solution for the system of equations is (-2,-6)