$$m\left(2a+b\right)+u\left(2a+b\right)$$

$$\left(m^2n^{-4}\cdot m^3n^2\right)^{-1}$$

$$6\sin\left(a\right)+4=2sin\left(a\right)+8$$

$$\left(+\:15\right)\:.\:\left(-\:3\right)\:+\:\left(-\:4\right)\:.\:\left(+\:5\right)\:$$

$$x-7=-6$$

$$2x^2\le6x-3$$

$$\frac{x}{y\left(x^2-1\right)}=\frac{dy}{dx}$$