(a^2-ab)/(b)cdot (2b^2)/(a^2)-b^(2)=

To simplify the given expression, we can follow these steps:<br /><br />$\frac {a^{2}-ab}{b}\cdot \frac {2b^{2}}{a^{2}-b^{2}}$<br /><br />Step 1: Factor out common terms in the numerator and denominator.<br />$\frac {a(a-b)}{b}\cdot \frac {2b^{2}}{(a-b)(a+b)}$<br /><br />Step 2: Cancel out the common terms in the numerator and denominator.<br />$\frac {a(a-b)}{b}\cdot \frac {2b^{2}}{(a-b)(a+b)} = \frac {a}{b}\cdot \frac {2b^{2}}{a+b}$<br /><br />Step 3: Simplify the expression.<br />$\frac {a}{b}\cdot \frac {2b^{2}}{a+b} = \frac {2ab^{2}}{b(a+b)} = \frac {2ab}{a+b}$<br /><br />Therefore, the simplified expression is $\frac {2ab}{a+b}$.