$-2.7+\left(-0.7\right)+\left(-4.2\right)$

$\frac{\left(a-b\right)^2}{c}$

$-7b-1b$

$\lim_{x\to0}\left(\frac{7^x-2^x}{6x}\right)$

$\int x\left(\frac{1}{x^2}+\frac{1}{3}\right)\left(\frac{6}{x^3}-\frac{8}{x^4}\right)dx$

$\int\left(\frac{3t-4}{2t-4}\right)dx$

$5\left(0.000152\right)$