Question

tìm n

a,7 chia hết 2n-1

b,3n-5 chia hết 2-n

ai nhanh nhất mk tk cho ^_^$$$$$$$$$$$

Answer 1

a

=> \(2n-1\inƯ_{\left(7\right)}=\left\{-1;1;7;-7\right\}\)

Nếu 2n-1=1 =>n= \(\left(1+1\right):2=1\)

nếu \(2n-1=-1\Rightarrow n=\left(-1+1\right):2=0\)

nếu \(2n-1=7\Rightarrow n=\left(7+1\right):2=4\)

nếu \(2n-1=-7\Rightarrow n=\left(-7+1\right):2=-3\)

Answer 2

a,n=1                       n=4

b,từng nớ(tra gu gồ nhé)