Bài `1:`
`1) 11 3/13 - (2 4/7 + 5 3/13)`
` = 11 + 3/13 - ( 2 + 4/7 + 5 + 3/13)`
` = 11 + 3/13 - 2 - 4/7 - 5 - 3/13`
` = (11-2-5) + (3/13-3/13) - 4/7`
` = 4 - 4/7`
` = 28/7 - 4/7`
` = 24/7`
`2) 4/7 + 5/6 : 5 - 0,375 . (-2)^2`
` = 4/7 + 1/6 - 3/8 . 4`
` = 4/7 + 1/6 - 3/2`
` = 24/42 + 7/42 - 63/42`
` = -16/21`
`3) 1/4 + 3/4.(1/2 + 2/3)`
` = 1/4 + 3/4 . 7/6`
` = 1/4 + 7/8`
` = 9/8`
Bài `2:`
`a) (3 1/2 +2x). 2 2/3 = 5 1/3`
`=> (7/2 + 2x) . 8/3 = 16/3`
`=> 7/2 + 2x = 16/3 : 8/3`
`=> 7/2 + 2x = 2`
`=> 2x = 2 - 7/2`
`=> 2x = -3/2`
`=> x = -3/2 : 2`
`=> x = -3/4`
Vậy `x=-3/4`
`b) |2x+3|=5`
`=> 2x+3=5` hoặc `2x+3=-5`
`+) 2x + 3 = 5`
`=> 2x = 2`
`=> x = 1`
`+) 2x+3=-5`
`=> 2x = -8`
`=> x = -4`
Vậy `x\in{1;-4}`
