$3x-4<x$

$\frac{2}{3}x-x$

$25a^2+49b^4-24b^4$

$\tan^2\left(x\right)\left(\cos^2\left(x\right)+1\right)+\cos^2\left(x\right)=\sec^2\left(x\right)$

$\frac{1-\tan^2\left(x\right)\cdot\cos^2\left(x\right)}{\cos^2\left(x\right)}$

$-4a-2b-4b-3-3a-7$

$\frac{x^2-2ax+a^2}{x^2-a^2}$