hi,

i don't understand how i would find the gradient at the following points at the given points:

y=3/x+2x+1 x=7

i know i would do:

y=3x^-1+2x+1

dy/dx=-3x^-2+2

im stuck after this because is i substitute it it looks like this:

dy/dx=-21^-2+2

what would i do from here??

thanks!