Question

8ab/a+8b*(a/8b-8b/a) при a = 8корень из 5 +6, b = корень из 5 - 3

Answer 1

$frac{8ab}{a+8b} *(frac{a}{8b}-frac{8b}{a})=frac{8ab}{a+8b} *frac{a^2-(8b)^2}{8ab} =frac{(a-8b)(a+8b)}{a+8b} =a-8b=8sqrt{5} +6-8sqrt{5} -3=\=6-3=3;$