Question

упростить выражение СРОЧНО

Answer 1

$\displaystyle 1)\frac{1-4a^2}{6}:(a-\frac{a+1}{3})=\frac{(1-2a)(1+2a)}{6}:\frac{3a-(a+1)}{3}=\\\\\frac{-(2a-1)(1+2a)}{6}:\frac{3a-a-1}{3}=\frac{-(2a-1)(1+2a)}{6}:\frac{2a-1}{3}=\\\\\frac{-(2a-1)(1+2a)}{6}*\frac{3}{2a-1}=\frac{-(1+2a)}{2}=-\frac{1+2a}{2}\\ \\2)(\frac{x}{x-1}-\frac{x}{1+x}-\frac{x^2+1}{1-x^2})*\frac{1}{(x+1)^2}=\\(\frac{x}{x-1}-\frac{x}{1+x}-\frac{x^2+1}{(1-x)(1+x)})*\frac{1}{(x+1)^2}=\frac{1}{(x-1)(x+1)}=\frac{1}{x^2-1}$