Question

Solve the system of equations. y=4x+5y=x2+12x+20

Answer 1

`\begin{pmatrix}x=-3,\:&y=-7\\ x=-5,\:&y=-15\end{pmatrix}\\`

Explanation:

`\begin{bmatrix}y=x^2+12x+20\\ y=4x+5\end{bmatrix}`

`\mathrm{Subtract\:the\:equations}`

`y=x^2+12x+20`

`y-y=x^2+12x+20-\left(4x+5\right)`

`\mathrm{Simplify}`

`0=x^2+8x+15`