$\lim_{x\to3}\sqrt{x^2-25}$

$m^2-21m+98$

$x\left(y-1\right)dx+y\left(x-1\right)dy$

$\frac{d}{dx}\left(e^{-3x}y\right)$

$3x+4<16$

$\frac{1+\sin\left(a\right)+\cos\left(a\right)}{\sin\left(a\right)-1+\cos\left(a\right)}$

$-\left[-1+\left(4+1\right)\right]+\left(-3+5\right)$