Question

Вычислите:
√18+√32-√128

Answer 1

$sqrt{18} = sqrt{2*9} = sqrt{2*3^{2} }=3 sqrt{2}$
$sqrt{32} = sqrt{2*16} = sqrt{2*4^{2} }=4 sqrt{2}$
$sqrt{128}= sqrt{2*64}= sqrt{2*8 ^{2} } =8sqrt{2}$
$sqrt{18}+sqrt{32}-sqrt{128}=3 sqrt{2}+4 sqrt{2}-8 sqrt{2} = (3+4-8)*sqrt{2} =- sqrt{2};$