$\left(x^2-10x\right)+\left(4y^2-40y\right)+100=0$

$\left(x+3.5\right)^2$

$-\left(-8\right)+\left(+1\right)$

$\log\left(\frac{x}{2}\right)=\log18-\log\left(x\right)$

$\lim_{x\to0}\left(1+2ax^2\right)^{\frac{b}{x^2}}$

$-7\left(-4\right)-2$

$\left(4\right)\cdot\left(9\right)\cdot\left(-6\right)\cdot\left(-1\right)$