Question

Galera me ajudem por favor

Answer 1

$(a+b)^2=a^2+2ab+b^2$

$\left(\dfrac{x^2}{2}+\dfrac{y^2}{2}\right)^2=\left(\dfrac{x^2}{2}\right)^2+2\cdot\dfrac{x^2}{2}\cdot\dfrac{y^2}{2}+\left(\dfrac{y^2}{2}\right)^2$

$\left(\dfrac{x^2}{2}+\dfrac{y^2}{2}\right)^2=\dfrac{x^4}{4}+\dfrac{x^2y^2}{2}+\dfrac{y^4}{4}$