Question

решите пожалуйста.
√32+√18-√50;
(7√8-√98+√10)√2;
(√5-√18)(√5-2√2)

Answer 1

$sqrt{32} + sqrt{18} - sqrt{50} = sqrt{16*2} + sqrt{9*2} - sqrt{25*2} =$$4 sqrt{2} +3 sqrt{2} - 5sqrt{2} = 2sqrt{2}$
$(7 sqrt{8} - sqrt{98} + sqrt{10} ) sqrt{2} =(7 sqrt{4*2} - sqrt{49*2} + sqrt{4*2.5} ) sqrt{2} =$$(14 sqrt{2} -7 sqrt{2} + 2sqrt{2.5} ) sqrt{2} =(7 sqrt{2} + 2sqrt{2.5} ) sqrt{2} =7*2+2sqrt{2.5*2}$=$14+2sqrt{5}$
$( sqrt{5} - sqrt{18} ) ( sqrt{5} -2 sqrt{2} )=$$sqrt{5} *sqrt{5} - sqrt{18} *sqrt{5} -sqrt{5}*2 sqrt{2} +2 sqrt{2} *sqrt{18} =$$5+ sqrt{9*2*2} -2 sqrt{10} +2 sqrt{36} =5+6-2 sqrt{10} +12=23-2 sqrt{10}$