$2a-b=-3$

$\left(x^2-2x+1\right)-\left(x-1\right)$

$-8y+3-7y+14$

$\lim_{x\to0}\left(\frac{\ln\left(1+x\right)+\ln\left(1-x\right)}{x\sin\left(x\right)}\right)$

$7x\text{4^2}4fr^4hfhf$

$\int\frac{\left(9x+16x^3\right)}{\left(9x^2+8x^4\right)}dx$

$-\left|\left(+361\right)-\left(-273\right)+562\right|+\left(-138+89\right)$