Simplify: x2−1x2+x⋅x2x−1\frac{x^2 - 1}{x^2 + x} \cdot \frac{x^2}{x - 1}x2+xx2−1⋅x−1x2 (assume x≠0,1,−1x \neq 0, 1, -1x=0,1,−1).
x+1x + 1x+1
x−1x - 1x−1
x+1x−1\frac{x+1}{x-1}x−1x+1
xx+1\frac{x}{x+1}x+1x