$\left(20\right)^{50}$

$\left(5r+4\right)\left(5r-4\right)=5r^2-16$

$\left(\frac{sin\left(x\right)+sin\left(x\right)^2}{cos\left(x\right)+sin\left(x\right)cos\left(x\right)}\right)$

$\left(y+2x\right)\left(x^2+xy-y^2\right)$

$\int\frac{9x+4}{\left(18x^2+16x\right)^5}dx$

$\int\left(x\sqrt{3x+7}\right)dx$

$\int\left(\ln\left(7x-2\right)\right)dx$