Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

222-9+11+12:2*14+14 = ? ( )

Toán Lớp 6: Nhanh =hn A=1/10+1/15+1/21+..+1/120

Toán Lớp 6: Nhanh =hn
A=1/10+1/15+1/21+..+1/120

Comments ( 2 )

  1. A = 1/10+1/15+1/21+. . . +1/120
    1/2A=1/20+1/30+1/42+. .  .+1/240
    1/2A=1/4.5+1/5.6+1/6.7+. . . +1/15.16
    1/2A=1/4-1/5+1/5-1/6+1/6-1/7+. . .+1/15-1/16
    1/2A=1/4-1/16
    1/2A=3/16
    A = 3/16:1/2
    A = 3/8
     

  2. A =1/10+1/15+1/21+…..+1/120
    1/2A = 1/20+1/30+1/42+…1/240
    1/2A= 1/4×5+1/5×6+1/6×7+…1/15×16
    1/2A = (1/4-1/5)+(1/5-1/6)+(1/6-1/7)+…+ (1/15-1/16)
    1/2A = 1/4 – 1/6
    1/2A = 3/16
    A = 3/16 x 2
    A = 3/8
    xin ctlhn ạ

Leave a reply

222-9+11+12:2*14+14 = ? ( )