$\int6x\cdot\cos\left(2x\right)dx$

$y-10=x$

$\left(2x+3\right)\left(4x^2+6x+9\right)$

$\cos\left(7x\right)\cos\left(4x\right)+\sin\left(7x\right)\sin\left(4x\right)$

$169b^{\left(4\right)}+200b^{\left(2\right)}+144+112b^{\left(2\right)}-112b^{\left(2\right)}$

$\int\frac{\sqrt{a+x^2}}{x}dx$

$\left(x^2-1\right)+\left(x^2+1\right)$