Question

If f(x)=x*−81 and g(x)=(x−9)−1(x+9), find g(x)×f(x).

Answer 1

f(x) = x²-81

g(x) = (x-9) -1(x+9)

= (x-9) -x-9


g(x) • f(x)



= [x²-81 ] • [ (x-9) -x-9 ]

=[ x²-81 ] • [ (x-x -9-9) ]
= [ x²-81 ] •[0-18]
= [ x²-81] •[ -18]

= -18•x² +-81•-18
= -18x²+1458