Answer
a) $x^{-3}+C$
b) $\dfrac{-x^{-3}}{3}+C$
c) $\dfrac{-x^{-3}}{3}+x^2+3x+C$
Work Step by Step
a) The anti-derivative is:
$\dfrac{-3}{-4+1}x^{-4+1}+C=x^{-3}+C$
b) The anti-derivative is:
$\dfrac{1}{-4+1}x^{-4+1}+C=\dfrac{-x^{-3}}{3}+C$
c) The anti-derivative is:
$\dfrac{1}{-4+1}x^{-4+1}+\dfrac{2}{1+1}x^{1+1}+3x+C=\dfrac{-x^{-3}}{3}+x^2+3x+C$