Question

b - 2a/( a-b)∙(a^2-b^2)/4a при a=2, b=1

Answer 1

$frac{b-2a}{ frac{(a-b)*(a^{2}- b^{2})}{4a}}$, при a=2, b=1 ⇒

$frac{1-2*2}{ frac{(2-1)*(2^{2}- 1^{2})}{4*2} }$ = $frac{1-4}{ frac{(1)*(4-1)}{8} }$ =  $frac{-3}{ frac{1*3}{8} }$ = $- frac{3}{ frac{3}{8} }$ = $- frac{1}{ frac{1}{8} }$ = $-frac{1}{8}$