Question 841263
{{{f(x)=x^2-5x}}}
{{{f(x+h)=(x+h)^2-5(x+h)}}}
{{{f(x+h)=(x^2+2xh+h^2)-5x-5h}}}
{{{f(x+h)-f(x)=(x^2+2xh+h^2)-5x-5h-x^2+5x}}}
{{{f(x+h)-f(x)=2xh+h^2-5h}}}
{{{(f(x+h)-f(x))/h=2x+h-5}}}
{{{lim(x->0,((f(x+h)-f(x))/h)=2x-5)}}}