Question

calcule as operações indicadas:
$a)2 \sqrt{10}+20 \sqrt{10}-15 \sqrt{10} = b)3 \sqrt{8}- \sqrt{18} = d)5 \sqrt[3]{4}+4 \sqrt[3]{4-20 \sqrt[3]{4} } =$

Answer 1

$a) 2 \sqrt{10} + 20\sqrt{10} - 15 \sqrt{10} =$
$(2+20-15) \sqrt{10} =$
$7 \sqrt{10}$

$b) 3 \sqrt{8} - \sqrt{18} =$
$3\sqrt{2 ^{3} } - \sqrt{9*2} =$
$3 \sqrt{2^3} - 3\sqrt{2}$
$3 \sqrt{2*2*2} - 3 \sqrt{2} =$
$3 \sqrt{4*2} - 3 \sqrt{2} =$
$6 \sqrt{2} - 3 \sqrt{2} =$
$(6-3)\sqrt{2} =$
$3 \sqrt{2}$