Question

найдите значение выражения

Answer 1

$frac{2a}{4a^{2}-10ab} - frac{5b}{4a^{2}-25b^{2}}= frac{2a}{2a(2a-5b)} - frac{5b}{(2a-5)(2a+5b)}= \ = frac{2a(2a+5b)-10ab}{2a(4a^{2}-25b^{2})} = frac{4a^{2}+10ab-10ab}{2a(4a^{2}-25b^{2})}= \ = frac{4a^{2}}{2a(4a^{2}-25b^{2})} = frac{2a}{(4a^{2}-25b^{2})}= \ = frac{10}{4*25 - 25*( sqrt{3})^2 }= frac{10}{100-75}= frac{10}{25}= 0,4$