Lê Quốc Trần Anh Coordinator
28/12/2017 at 17:52-
Alone 28/12/2017 at 18:23Put the number to find is:a
We have:a divided 7 residual 3 so put a=7k+3 (k\(\in N\)) \(\Rightarrow a+39=7k+42⋮7\)
a divided 4 residual 1 so put a=4m+1 \(\left(m\in N\right)\) \(\Rightarrow a+39=4m+40⋮4\)
a divided 3 residual 0 so put a=3n\(\left(n\in N\right)\) \(\Rightarrow a+39=3n+39⋮3\)
So a+39\(\in BC\left(7,4,3\right)\) .Because a+39 is the smallest so a+39=\(BCNN\left(3,7,4\right)=84\)
\(\Rightarrow a=45\)
Answer:the number to find is 45
Lê Quốc Trần Anh selected this answer. -
FA Liên Quân Garena 30/12/2017 at 21:50Put the number to find is:a
We have:a divided 7 residual 3 so put a=7k+3 (k∈N
) ⇒a+39=7k+42⋮7
a divided 4 residual 1 so put a=4m+1 (m∈N)
⇒a+39=4m+40⋮4
a divided 3 residual 0 so put a=3n(n∈N)
⇒a+39=3n+39⋮3
So a+39∈BC(7,4,3)
.Because a+39 is the smallest so a+39=BCNN(3,7,4)=84
⇒a=45
Answer:the number to find is 45