Question

If anyone could help, would be much appreciated

Answer 1

f(x+h)-f(x)/h=5h+10x-6

Explanation:

f(x)=5x²-6x+1

f( x+h )=5( x+h )²-6(x+h)+1

=5(x²+h²+2hx)-6x-6h+1

=5x²+5h²+10xh-6x-6h+1

f(x+h)-f(x)=(5x²+5h²+10xh-6x-6h+1-(5x²-6x+1)

=5x²+5h²+10xh-6x-6h+1-5x²+6x-1

=5h²+10hx-6h

f(x+h)-f(x)/h=(5h²+10hx-6h)/h

=5h+10x-6