Question

$5 \sqrt{18} + \sqrt{12} - 3 \sqrt{20} + \sqrt{72} +$
$\sqrt{45} =$

VA ROG FRUMOS REPEDE DAU COROANA

Answer 1

rad18=rad(2×3^2)=3rad2 =>5rad18=15rad2
rad12=rad(2^2×3)=2rad3
rad20=rad(2^2×5)=2rad5 =>3rad20=6rad5
rad72=rad(2^3×3^2)=6rad2
rad45=rad(3^2×5)=3rad5

15rad2+2rad3-6rad5+6rad2+3rad5=
21rad2+2rad3-3rad5