$\lim_{x\to\infty}\left(1+\frac{4}{x}\right)^{1.5x}$

$\lim_{x\to\infty}\left(\frac{5\cdot x^2+1}{e^x}\right)$

$\left(3-secx\right)\left(9+3secx+sec^2x\right)$

$\left(3\right)x\left(-12\right)$

$\left(2x^3y-z\right)^2$

$5g^2-u^3+\left(gu\right)^2+g+u-18$

$-3y-9x+6=0$