$f(x)=4x^2+5x$f(x)=4x^2+5x

$f(x)=3x^3+2x^2$f(x)=3x^3+2x^2

$\displaystyle f(x)= \frac{1}{3}x^3+2x$\displaystyle f(x)= \frac{1}{3}x^3+2x

$f(x)=\left(4x+1\right)^2$f(x)=\left(4x+1\right)^2