Question

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

Answer 1

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