$7x^2\cdot7$

$2g+\left(-4g\right)$

$2a^2,\:3a^2$

$\int\frac{\sec^2\left(x\right)}{\tan^3\left(x\right)-\tan^2\left(x\right)}dx$

$\lim_{x\to\infty}\left(\sqrt[2]{\left(x^2+x+1\right)}-1\right)$

$\lim_{x\to0}\left(\frac{sin5x}{sim3x}\right)$

$\left(\frac{7}{2}\right)\left(7x\right)$