$\lim_{x\to7}\left(\frac{x^2-14x+49}{x-7}\right)$

$\frac{x^2-4x+3}{x}$

$144y^2-72y+9$

$\int_0^{\frac{3\pi}{2}}\left(xcos\left(x\right)\right)dx$

$\frac{\sin^2\left(x\right)}{\cos^2\left(x\right)}\left(1-\sin\left(x\right)^2\right)=1-\cos\left(x\right)^2$

$x-8+x+x-8+x$

$a^2-18a+17$