most general antiderivative?

Question

F(x)=7x^2/5-9x^4/5

Use C to denote an arbitrary constant

Answer 1

f(x) = 7x^2/5 - 9x^4/5

∫(7x^2/5 - 9x^4/5)dx
= 7(5/7x^7/5) - 9(5/9x^9/5) + C
= 5x^7/5 - 5x^9/5 + C

Answer 2

What you have here is of the form
ax^k1 - bx^k2
so the general form of the antiderivative is going to be
(a/(k1 + 1))X^(k1 +1) - (b/(k2 + 1))x^(k2 +1) + C.

HTH

Doug