Question

Решить примеры:
1) $sqrt{8m$-0,2$sqrt{200m$+3$sqrt{72m$

2)$sqrt{32$+$sqrt{18$-$sqrt{30$

3) $frac{7+V7}{V7}$√

4) $frac{12}{7V2}$

5)$frac{5}{4V5} }$

Answer 1

$sqrt{8m}-0,2 sqrt{200m}+3 sqrt{72m}=2 sqrt{2m}-0,2*10 sqrt{2m}+3*6 sqrt{2m} =\=2 sqrt{2m} -2 sqrt{2m} +18 sqrt{2m}=18 sqrt{2m}\ sqrt{32}+ sqrt{18} - sqrt{30}=4 sqrt{2}+3 sqrt{2}- sqrt{30}=7 sqrt{2}- sqrt{30}\ frac{7+ sqrt{7} }{ sqrt{7} }= frac{7 sqrt{7}+7 }{7}= sqrt{7}+1\ frac{12}{7 sqrt{2} } = frac{12 sqrt{2} }{14} = frac{6 sqrt{2} }{7} \ frac{5}{4 sqrt{5} } = frac{ sqrt{5} }{4}$