$\sqrt{7}+2\sqrt{7}$

$\left(\frac{3}{5}x+\frac{4}{9}\right)^2$

$\frac{3}{4}^{\left(-2\right)\left(3\right)}4^3\:-\left(-2\right)^2\:\left(3\right)^3\left(4\right)^2+\:\left(-2\right)^3\:\left(3\right)^2\:4^3-\frac{1}{2}$

$y=\left(x^5-2x^2\right)^3\left(4x^3-5\right)^4$

$\left[9ab+3\left(4y\right)\right]^2\:\left[9ab+3\left(4y\right)\right]^2$

$\int_1^3\pi\left(x-1\right)dx$

$\left(3u^2\right)\left(5u^{-8}\right)$