Toán Lớp 9: √1/20 √1/60 3/98 √3/20+√1/60-2√1/15

Question

Toán Lớp 9:  √1/20 √1/60 3/98 √3/20+√1/60-2√1/15

ngochuong2k2 · Answer

&radic;1/20       1/(2*căn bậc hai(5))    &radic;1/60     1/(2*căn bậc hai(15))      &radic;3/98     căn bậc hai(3)/(7*căn bậc hai(2))     &radic;3/20+&radic;1/60-2&radic;1/15     -0.001/27^(1/2)     xin hay nhất      no copy nha      ch&uacute;c bn học tốt

aivilanlan · Answer

a)  sqrt{(1)/(20)}   =( sqrt{1})/( sqrt{20})   =( sqrt{20}. sqrt{1})/( sqrt{20}. sqrt{20})   =( sqrt{20})/(20)   =(2 sqrt{5})/(20)   = sqrt{5}/(10)   b)  sqrt{(1)/(60)}   =( sqrt{1})/( sqrt{60})   =( sqrt{1}. sqrt{60})/( sqrt{60}. sqrt{60})   =( sqrt{60})/(60)   =(2 sqrt{15})/(60)   =( sqrt{15})/(30)   c)  sqrt{(3)/(98)}   =( sqrt{3})/( sqrt{98})   =( sqrt{3}. sqrt{98})/( sqrt{98}. sqrt{98})   =( sqrt{294})/(98)   =(7 sqrt{6})/(98)   =( sqrt{6})/(14)   d)  sqrt{3/(20)}+ sqrt{(1)/(60)}-2 sqrt{1/(15)}   =( sqrt{3})/( sqrt{20})+( sqrt{1})/( sqrt{60})-2.( sqrt{1})/( sqrt{15})   =( sqrt{3}. sqrt{20})/( sqrt{20}. sqrt{20})+( sqrt{1}. sqrt{60})/( sqrt{60}. sqrt{60})-2.( sqrt{1}. sqrt{15})/( sqrt{15}. sqrt{15})   =( sqrt{60})/(20)+( sqrt{60})/(60)-(2 sqrt{15})/(15)   =(2 sqrt{15})/(20)+(2 sqrt{15})/(60)-(2 sqrt{15})/(15)   =2 sqrt{15}(1/(20)+1/(60)-1/(15))   =2 sqrt{15}((3)/(60)+(1)/(60)-(4)/(60))   =2 sqrt{15}.0   =0