$15a^2-6ab-8a^2+20-5ab-31+a-b$

$\left(2e^{2x}siny+2xy\right)dx+\left(e^{2x}cosy+x^2\right)dy=0$

$00342rf4f$

$\lim\:_{x\to\:\infty\:}\left(\frac{\left(4x\right)cos\left(2x\right)-sen\left(2x\right)}{4\left(x^3\right)}\right)$

$\log_{10}\left(\frac{x}{3}\right)=-6$

$-5.38\cdot1.2$

$14+-6+-6+3+2$