2=6
3=12
4=20
5=30
6=42
9=???????????
Xém xem các tổng sau có chia hết cho 6 không?
a) A= 54+72+96+138
b) B= 42+94+17+61
c) C= 78+124+306+91+504+205
Giúp em với em đang cần gấp ạ ^_^
A , B không chia hết cho 6 .
C chia hết cho 6
C=-66×(1/2-1/3+1/11)+124×-37+63×-124
RC=-66×(1/2-1/3+1/11)+124×-37+63×-124
C=-66×(1/2-1/3+1/11)+124×-37+63×-124
\(C=-66\times(\frac{1}{2}-\frac{1}{3}+\frac{1}{11})+124\times-37+63\times-124\)
\(C=-66\times\frac{17}{66}-124\times100\)
\(C=-12417\)
#)Giải :
\(C=\left(-66\right).\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{11}\right)+124.\left(-37\right)+63.\left(-124\right)\)
\(C=\left(-66\right).\frac{17}{66}-4699-7812\)
\(C=\left(-17\right)-4699-7812\)
\(C=-12528\)
C = -66.(1/2 - 1/3 + 1/11) + 124.(-37) + 63.(-124)
C = -66.(1/2 - 1/3 + 1/11) - 124.37 - 63.124
C = -17 - 4588 - 7812
C = -12417
RC=-66×(1/2-1/3+1/11)+124×-37+63×-124
C=-66×(1/2-1/3+1/11)+124×-37+63×-124
C=-66×(1/2-1/3+1/11)+124×-37+63×-124
C=-66×(1/2-1/3+1/11)+124×-37+63×-124
tinh : C=-66.(1/2-1/3+1/11)+124.(-37)+63.(-124)
C=-66.(\(\dfrac{1}{2}-\dfrac{1}{3}\)+\(\dfrac{1}{11}\))+124.(-37)+63.-124
=-66.\(\dfrac{17}{66}\)-4699-7812=-17-4699-7812=-12528
chúc bạn học tốt nhaNguyễn Thái Nghĩa
Tính :
-66 . \((\dfrac{1}{2} - \dfrac{1}{3}+\dfrac{1}{11})\) + 124 . ( -37 ) + 63 . ( -124 )
\(-66.\left(\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{11}\right)+124.\left(-37\right)+63.\left(-124\right)\)
\(=-66.\dfrac{17}{66}+124.\left(-37-63\right)\)
\(=-17+124.\left(-100\right)=-17-12400\)
\(=-12417\)
Tính :
-66 . ( \(\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{11})\)+ 124 . (-37) + 63 . (-124)
= -66 . (\(\dfrac{33}{66}-\dfrac{22}{66}+\dfrac{6}{66}\))+ (-4588) + (-7812)
= -66 . \(\dfrac{17}{66}\)+ (-12400)
= -17 + (-12400)
= -12417