Question

Spuneti-mi raspunsul la acest exercitiu: $-7,5(4- \sqrt{8} )^{2}$

Answer 1

$-7,5(4- \sqrt{8} )^2=-7,5(4-2 \sqrt{2} )^2=7,5[4^2-2 \cdot 4 \cdot 2 \sqrt{2} +(2 \sqrt{2} )^2]= \\ =-7,5(16-16 \sqrt{2} +8)=-7,5(24-16 \sqrt{2} )=-180+120 \sqrt{2}$