$\frac{sen\left(\frac{\left(x+1\right)}{\sqrt{y}}\right)}{cos\left(\frac{\left(x+1\right)}{\sqrt{y}}\right)}$

$\left(x-\frac{2}{5}\right)\left(x+\frac{2}{5}\right)$

$\lim\:\:x\to\infty\left(\frac{\sqrt{1+x}-\sqrt{1-x}}{x}\right)$

$\left(625\:x\:48\right)\frac{1}{4}$

$x^2+10x+5+25$

$7x\left(x^3-2x\right)^2$

$9c+9d^2$