$5x-15+2y+8-\frac{7y}{3}+\frac{14x}{3}-\frac{21}{3}-8$

$\left(x^{\left(4\right)}+x^{\left(3\right)}+x^{\left(2\right)}+x+1\right)-\left(x^{\left(5\right)}+x^{\left(4\right)}+x^{\left(3\right)}+x^{\left(2\right)}+x+1\right)$

$4x-5-6x+1$

$3\left(40x+9\right)$

$\left(1-2x\right)^{-\frac{1}{4}}$

$12,5-4,02\:x\:3,1+12,43-7,56$

$lny=\cos\left(x\right)\ln\left(1-3x\right)$