Cho biểu thức P = (1+x/1-x - 1-x/1+x - 2x^2/x^2-1) : x^2+4x+4/(x+1)(x+2) a) Rút gọn P.
Giải thích
P=1+x2−1−x2+2x21−x.1+x:x+22x+1.x+2 =1+2x+x2−1+2x−x2+2x21−x1+x:x+2x+1 =2x(x+2)1−x1+x⋅1+xx+2 =2x1−x
P=1+x2−1−x2+2x21−x.1+x:x+22x+1.x+2 =1+2x+x2−1+2x−x2+2x21−x1+x:x+2x+1 =2x(x+2)1−x1+x⋅1+xx+2 =2x1−x