$$17\:+21+\:18\:+27+\:17\:21+\:20\:+22\:+18+\:23$$

$$x^2-1=99$$

$$49^2-84m+36$$

$$cos\left(u+v\right)+cos\left(u-v\right)=2cos\:u\:cos\:v$$

$$u^2-4u+3$$

$$\left(1\frac{1}{5}g^2v\right)^2-\left(2\frac{2}{3}d^3x^2\right)^2$$

$$4x^3-6x+2+3x^2+2-6$$