$d^{-5}.d^9.d^4$

$9a^2-12a^2b+4a^29^2$

$x^2-49y^2$

$\frac{u}{2}-5\le-9$

$e=\frac{\cos\left(100^{\circ}\right)+\cos\left(10^{\circ}\right)+\cos\left(40^{\circ}\right)}{\cos\left(50^{\circ}\right)+\cos\left(cos30^{\circ}\right)}$

$6x^2+19x-10=0$

$\int\frac{1}{\sqrt{\left(x^2-2x+10\right)^3}}dx$