$17-\left(+1\right)+\left(1\right)$

$\lim_{x\to1}\left(\frac{3\cos\left(1-x\right)}{\left(x\right)\left(1+3\ln\left(x\right)\right)}\right)$

$\left(5x+12\right)\left(5x-10\right)$

$\lim_{x\to3}\left(\frac{x-3}{2x}-3x\right)$

$\lim_{x\to\infty}\left(\frac{5x^9}{3e^x+5}\right)$

$-36\cdot16$

$2+4\tan\left(a\right)^2$