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 7: Cho abc + deg chia hết cho 37 thì abcdeg chia hết cho 37. Cho abc – deg chia hết cho7 thì abcdeg chia hết cho 7.

Toán Lớp 7: Cho abc + deg chia hết cho 37 thì abcdeg chia hết cho 37.
Cho abc – deg chia hết cho7 thì abcdeg chia hết cho 7.

Comments ( 1 )

  1. a) Ta có:
    +) abc + deg  = abc + 100d + 10e + g vdots 37
    +) abcdeg = 1000abc + 100d + 10e + g
    => 1000abc + 100d + 10e + g – (abc + 100d + 10e + g) = 999abc
    mà 999 vdots 37
    => 999abc vdots 37
    => abcdeg vdots 37 (đpcm)
    b) Ta có:
    +) abc – deg  = abc – 100d – 10e – g vdots 7
    +) abcdeg = 1000abc + 100d + 10e + g
    => 1000abc + 100d + 10e + g + (abc – 100d – 10e – g) = 1001abc
    mà 1001 vdots 7
    => 1001abc vdots 7
    => abcdeg vdots 7 (đpcm)
    (Chúc bạn học tốt)
     

Leave a reply

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

About Madelyn