Question

Даю 50 баллов за решение!
Упростите выражение
(1/2а²-1/5b²)×(1/2a²+1/5b2)-(1/4a²-1/5b²)²

Answer 1

$(\frac{1}{2}a^2-\frac{1}{5}b^2)\cdot (\frac{1}{2}a^2+\frac{1}{5}b^2)-(\frac{1}{4}a^2-\frac{1}{5}b^2)^2=\\\\=(\frac{1}{4}a^4-\frac{1}{25}b^4)-(\frac{1}{16}a^4-\frac{2}{20}a^2b^2+\frac{1}{25}b^4)=\frac{3}{16}a^4+\frac{1}{10}a^2b^2-\frac{2}{25}b^2$