$x^2-5x+25=4$

$\frac{60+80}{2}$

$\left(6y^3-8xy^2-6xy^2\right)-\left(xy^2-6y^3+4\right)$

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

$-8-\left|-5+\left(-1+2-3\right)\right|+\left(4-1-8+2\right)+1$

$\left(1.5\right)^2-\left(3.9\right)^2+\left(-2.1\right)^3$

$2x\left(x+1\right)-5\left(x+2\right)\le7$