Find the break even points of the expression $x^2+4x=7x-8$

Find the derivative

$\frac{d}{dx}\left(\frac{2x^3}{\left(2-5x\right)\sqrt{x^2+1}}\right)$

Find the derivative

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

Find the derivative

$\frac{d}{dt}\left(\frac{\sqrt{t-4}}{tcos\left(t\right)}\right)$

Find the derivative

$\frac{d}{dx}\left(\frac{\left(x^5+3x\right)^4}{cos\:x}\right)$

Find the derivative

$\frac{d}{dx}\left(\frac{3}{x^2}\right)$

Find the derivative

$\frac{d}{dx}\left(\frac{5}{x}\right)$

Find the derivative

$\frac{d}{dx}\left(x^2+y^2\right)$