Question

Решите номер 21.Есть вложение.

Answer 1

$( frac{3}{a-4} + frac{4a-6}{a^2-3a-4} + frac{2a}{a+1} )cdot frac{a}{2a-3} = frac{3(a+1)+4a-6+2a(a-4)}{(a-4)(a+1)}cdot frac{a}{2a-3} = \ =frac{3a+3+4a-6+2a^2-8a}{(a-4)(a+1)}cdot frac{a}{2a-3} = frac{2a^2-a-3}{(a-4)(a+1)}cdot frac{a}{2a-3} = \ =frac{2(a-1.5)(a+1)}{(a-4)(a+1)}cdot frac{a}{2a-3} =frac{2(a-1.5)}{a-4}cdot frac{a}{2a-3} = frac{(2a-3)a}{(a-4)(2a-3)}=frac{a}{a-4}$
Ответ: $frac{a}{a-4}$