$\left(49-4\right):45+24:\left(2.4\right).\left(3.5-5\right)$

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

$\left(9x^6+3y^2\right)^2$

$\int_1^54xdx$

$\lim_{x\to\infty}\left(\frac{\sqrt{-x^2+16}}{x}\right)$

$-xy-3x^2-3x^2-3x$