Xin giúp mình toán lớp 4 ạ

Đáp án `+` Giải thích các bước giải :

`----------`

`(3times125+3times75)/(6times43+6times57)`

`=(3times(125+75))/(6times(43+57))`

`=(3times200)/(6times100)`

`=600/600`

`=1`

`----------`

`(15times42+57times15+15)/(100times40+50times2times2)`

`=(15times(42+57+1))/(100times40+100times2)`

`=(15times100)/(100times(40+2))`

`=(15times100)/(100times42)`

`=(15timescancel100)/(cancel100times42)`

`=15/42`

`=5/14`

`----------`

`(179times101-140-39)/(100times179)`

`=(179times101-(140+39))/(100times179)`

`=(179times101-179)/(100times179)`

`=(179times(101-1))/(100times179)`

`=(179times100)/(100times179)`

`=(cancel179timescancel100)/(cancel100timescancel179)`

`=1`

`----------`

`(4times5times7times8times9)/(8times10times14times4times3)`

`=(4times5times7times2times2times2times3times3)/(4times2times5times2times7times2times2times2times3)`

`=(cancel4timescancel5timescancel7timescancel2timescancel2timescancel2times3timescancel3)/(cancel4timescancel2timescancel5timescancel2timescancel7times2times2timescancel2timescancel3)`

`=3/(2times2)=3/4`

`----------`

`(12times13times15times18)/(24times13times30times9)`

`=(12times13times15times9times2)/(12times2times13times15times2times9)`

`=(cancel12timescancel13timescancel15timescancel9timescancel2)/(cancel12times2timescancel13timescancel15timescancel2timescancel9)`

`=1/2`

`----------`

`(13times45times72)/(36times26times90)`

`=(13times45times36times2)/(36times13times2times45times2)`

`=(cancel13timescancel45timescancel36timescancel2)/(cancel36timescancel13times2timescancel45timescancel2)`

`=1/2`

`----------`