Question

Помогите задача N4. Срочно

Answer 1

$S=a^2=(2 \sqrt{80}- \sqrt{5})^2=(2 \sqrt{16*5}- \sqrt{5})^2=(2*4 \sqrt{5}- \sqrt{5})^2=\\\\=(8 \sqrt{5}- \sqrt{5})^2=(7 \sqrt{5})^2=49*5=245$