Question

Помогите решить:
$\frac{ (a+b)^{2}- (a-b)^{2} }{4b}$
при a = 3,21, b = -0,325

Answer 1

$= \frac{( a^{2} +2ab +b^{2})-(a^{2}-2ab+b^{2})}{4b} = \frac{4ab}{4b} =a=3,21$