$\log_b\left(\frac{7}{8}\right)$

$\left(11x^2-6y^2-5\cdot\left(-\frac{1}{3}\cdot x+\frac{13}{9}\cdot y+13\right)^2\right)\cdot39$

$\lim_{x\to1}\left(\frac{\sqrt{x}-x^2}{1+\sqrt{x}}\right)$

$\int tan\left(2x+1\right)dx$

$\int x\left(150e^{-150x}\right)dx$

$49a^2x^2-64$

$-4\left(-6\right)\cdot\left(5-13\right)$