a)\(\overline{ab}\cdot101=\overline{ab}\cdot\left(100+1\right)\)
\(=\overline{ab}\cdot100+\overline{ab}\)
\(=\overline{ab00}+\overline{ab}\)
\(=\overline{abab}\)
b)\(\overline{abc}\cdot7\cdot11\cdot13=\overline{ab}\cdot1001\)
\(=\overline{ab}\cdot\left(1000+1\right)\)
\(=\overline{ab}\cdot1000+\overline{ab}\)
\(=\overline{ab000}+\overline{ab}\)
\(=\overline{ab0ab}\)
a) ab . 101 = abab
b) abc . 7 . 11 . 13 = abc . 1001 = abcabc
chết phần c mk nhìn nhầm thành ab xin giải lại
b) abc*7*11*13=abc*1001
=abc*(1000+1)
=abc*1000+abc
=abc000+abc
=abcabc
a) ab . 101
= ab . ( 100 + 1 )
= ab . 100 + ab
= ab00 + ab
= abab
b) abc . 7 . 11 . 13
= ab . 1001
= ab . ( 1000 + 1 )
= ab . 1000 . ab
= ab000 + ab
= ab0ab .