$$78=3u$$

$$\lim_{x\to0}\left(\frac{x^3+x^2-x-15}{2x^2-3}\right)$$

$$y^2+2y+1$$

$$\frac{d^3}{dx^3}\left(\frac{1}{12}+2x^2-x^3-\frac{1}{4}x^4\right)$$

$$35+12r+r^2$$

$$\frac{dy}{dx}=\frac{y\left(x-4\right)}{3x}$$

$$\left(-8\cdot4\right)+8$$