My homework is due within the hour online, and I can't seem to figure out this problem..
It says Evaluate F(3x+5)if f(x)=2x^2+2x+3
Now in the solutions manual it gives the follwing steps
I get the whole problem except for- how did they get the 30x in the 2nd step? Can someone please tell me how they got the 30x? Thanks!