Question

Решите : a^2-4b^2/2ab:(1/2b-1/a)=
При a=2 15/19 b= 5 2/19

Answer 1

$frac{ a^{2} - 4b^{2} }{2ab} : ( frac{1}{2b} - frac{1}{a})= frac{(a-2b)(a+2b)}{2ab} : frac{a-2b}{2ab}= frac{(a-2b)(a+2b)*2ab}{2ab*(a-2b)}=a+2b$

Если $a= 2frac{15}{19} , b= 5frac{2}{19}$ , то

$2 frac{15}{19}+2*5 frac{2}{19} = 2 frac{15}{19} + frac{2*97}{19} = 2frac{15}{19} +10frac{4}{19} =13$