Đáp án:
Bài 1 : Tính
`a, -1/12 - ( 25(5)/8 - 1/30 )`
`= -1/12 - ( 205/8 - 1/30 )`
`= -1/12 - 3071/120`
`= -1027/40`
`b, -1,75 - ( -1/9 - 2(1)/18 )`
`= -1,75 - ( -1/9 - 37/18 )`
`= 1,75 + 13/6`
`= 47/12`
`c, -5/6 - ( -3/8 + 1/10 )`
`= -5/6 +11/40`
`= -67/120`
`d, ( 2/5 + -4/3 ) + -1/2`
`= -14/15 + -1/2`
`= -43/30`
`e, ( 3/4 + -7/2 ) . ( 2/11 + ( 2/11 + 12/22 ))`
`= -11/4 . (2/11 + 8/11)`
`= -11/4 . 10/11`
`= -5/2`
Bài 2 :
`a, -2 . -38/21 . -7/4 . - 3/8`
`= (-2 . -3/8 ) . ( -38/21 . -7/4 )`
`= 3/4 . 19/6`
`= 19/8`
`b, 5/9 : ( 1/11 - 5/22 ) + 5/9 : ( 1/15 -2/3 )`
` = 5/9 : -3/22 + 5/9 : -3/5 `
`= 5/9 : ( -3/22 + -3/5) `
`= 5/9 : -81/110`
`= -550/729`
`Go od luck !`