$\frac{1}{4}xy^2\cdot\frac{1}{4}xy^2$

$\lim_{h\to0}17+\frac{28}{t+1}$

$0.8-\frac{7}{8}+\frac{7}{\frac{16}{\frac{1}{4}}}$

$\frac{\sin\left(x\right)}{1+\cos\left(x\right)}+\frac{1+\cos\left(x\right)}{\sin\left(x\right)}=2\cos\sec a$

$2x^2+1=9x-3$

$\frac{\left(sec\left(x\right)-cos\left(x\right)\right)}{cos\left(x\right)}$

$32a^2-72b^2$