Đáp án:
Bài 2 :
`a, 24/60 = (24 : 12 )/(60:12) = 2/5`
`b, 1010/4545 = (1010:505)/(4545:505) = 2/9`
`c, 176/495 = (176 : 11 )/(495 : 11 ) = 16/45`
`d, 505/808 = (505 : 101 )/ ( 808 : 101 ) = 5/8`
bài 3 :
`a, x/4 = 18/12 `
`-> x = 18` x `4 : 12 = 6`
Vậy `x = 6`
`b, 8/(x+5) = 4/3`
`-> x+5 = 3` x ` 8: 4 = 6`
`-> x = 6-5 =1`
Vậy `x=1`
`c, 4/x = 15/30`
`-> x = 30 ` x ` 4 : 15`
`-> x = 8`
Vậy `x = 8`
`Go od luck!`