5[x] (9[x^2]2 + 4)
The meaning is not very clear :/
Do you mean
\(5*x*(9x^2*2 + 4)\;\;\;?\)
ok i will assume that you do.
\(5*x*(9x^2*2 + 4)\\ =5x(18x^2+ 4)\\ =90x^3+20x\)
