Question

Find the x-intercepts of y = x2 + 15x + 56.(8, 0) and (7, 0)(8, 0) and (-7, 0)(-8, 0) and (7, 0)(-8, 0) and (-7, 0)

Answer 1

We want to find the x-intercept of the equation

`y=x^2+15x+56`

The x-intercept is the root of the equation which is gotten as making y to be 0, we have

`\begin{gathered} 0=x^2+15x+56 \\ x^2+15x+56=0 \\ x^2+8x+7x+56=0 \\ x(x+8)+7(x+8)=0 \\ (x+7)(x+8)=0 \\ x=-7 \\ x=-8 \end{gathered}`

So the x-intercept becomes

(-8, 0) and (-7, 0)

Note that y will be zero

Hence the answer is

(-8, 0) and (-7, 0)