$\frac{\left(-5\right)^4\cdot\left(-3\right)^7\cdot\left(-5\right)^3\cdot7^4}{7^3\cdot\left(-3\right)^4\cdot\left(-3\right)^3\cdot\left(-5\right)^6}$

$4\left(csc^2\theta\:-1\right)=csc^2\theta\:$

$y'=-xy$

$-\csc\left(x\right)\cdot\cot\left(x\right)$

$27m^4+3m^2-9mn$

$\left(2x+3y+2\right)^3$

$\left(x+6\right)\left(x+4\right)-\left(x+5\right)^2$