$$\frac{du}{dy}=u-y$$

$$\int\cos\left(e^{-x}\right)\cdot e^{-2x}dx$$

$$y=-\frac{3}{4}x-1$$

$$3ax-3bx-2ay+2by$$

$$\left(6-5+7\right)-\left(3-2-8\right)$$

$$16a^2b^4+48ab^2xy^3+36x^2y^6$$

$$\frac{4b+3y}{7b}-\frac{4b-2y}{3b}+1$$