Toán Lớp 7: C/M: 8^12-2^33-2^30 luôn chia hết cho 55
Helpppppp me
Leave a reply
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.
Toán Lớp 7: C/M: 8^12-2^33-2^30 luôn chia hết cho 55
Helpppppp me
Comments ( 2 )
=8^12-2^(3.11)-2^(3.10)
=8^12-(2^3)^11-(2^3)^10
=8^12-8^11-8^10
=8^10 . 8^2 – 8^10 . 8-8^10 . 1
=8^10 .(8^2-8-1)
=8^10 . (64-8-1)
=8^10 . (56-1)
=8^10 . 55
Ta có:
55\vdots55
=>8^10 . 55\vdots55
=>8^12-2^33-2^30(text{ĐPCM})
Vậy 8^12-2^33-2^30\vdots55