Question

I need help pleeeeeease thank youuuuu

Answer 1

So firstly, reverse the signs in (6x^2 + 8x - 1) and change the minus sign to a plus sign:

$\begin{alignedat}{2} 4x^2-9x+7\\ +(-6x^2)-8x+1\end{alignedat}$

Next, combine like terms:

$\begin{alignedat}{3} 4x^2-9x+7\\ +(-6x^2)-8x+1\\-2x^2-17x+8\end{alignedat}$

The difference is -2x^2 - 17x + 8