28.(231 + 69) +72. (231 + 69 )
=28. 300 +72. 300
= 300.(28+72)
= 300. 100
=30000
KB nha!!!
28.(231+69)+72.(231+69)=
28.231+28.69+72.231+72.69=
(28+72).231+(28+72).69=
100.231+100.69=
100.(231+69)=
100.300=30000
28.(231+69)+72.(231+69) = 28. 300 +72. 300 = 300.(28+72) = 300.100 = 30000