Let me know how to factor thisss. and give me the steps.

You have to find first the discriminant
∆=8^2-4*(-1) *(-7) =36
x=(-8±√36) /-2=(-8±6)/-2=4±3=1 or 7
So x(1)=1 or x(2)=7
-x^2+8x-7=[x-x(1) ][x-x(2) ]=(x-1) (x-7)

Multiplication property of zero