a) \(abc+5abc=6738\)
\(\Leftrightarrow6abc=6738\)
\(\Leftrightarrow abc=\frac{6738}{6}\)
\(\Leftrightarrow abc=1123\)
Đề cho không rõ bạn à. \(abc\)hay \(\overline{abc}\)?
a, abc + 5abcd = 6738
abc1 + 5abcd = 6738
abc ( 1 + 5 ) = 6738
abc6 = 6738
abc = 6738 : 6
abc = 1123
Làm lại :
a) \(\overline{abc}+\overline{5abc}=6738\)
\(100a+10b+c+5000+100a+10b+c=6738\)
\(200a+10b+2c=6738-5000\)
\(2\left(100a+10b+c\right)=1738\)
\(\overline{abc}=1738:2\)
\(\overline{abc}=869\)
b) \(\overline{abc}\cdot5=\overline{1abc}\)
\(5\cdot\left(100a+10b+c\right)=1000+100a+10b+c\)
\(500a+50b+5c=1000+100a+10b+c\)
\(500a-100a+50b-10b+5c-c=1000\)
\(400a+40b+4c=1000\)
\(4\left(100a+10b+c\right)=1000\)
\(\overline{abc}=250\)
Chú ý tới tính chất : \(\overline{abc}=100a+10b+c\)
