Đáp án:
`text{Bài 1:}`
a) `-19/36`
b) `32`
c) `-37/77`
`text{Bài 2:}`
a) `x = -1`
b) `x = -10/3`
Giải thích các bước giải:
`text{Bài 1:}`
a) `-7/12+11/18-5/9`
`=-21/36 + 22/36 - 20/36 =-19/36`
`b,1/7-8/7 : 8 - 3 : 3/4 . (-2)^3`
`=1/7 - 8/7 . 1/8-3 . 4/3 . (-8)`
`=1/7-1/7+32 = 32`
c) `1,4 . 15/49-(4/3+2/3):2 1/5`
`=3/7-2 . 5/11 =3/7-10/11 =-37/77`
`text{Bài 2:}`
a) `11/12 . x+3/4=-1/6`
`to 11/12. x=-1/6-3/4`
`to 11/12 . x=-11/12`
`to x=-11/12:11/12`
`to x=-1`
Vậy `x = -1`
b) `3-(1/6-x) . 2/3=2/3`
`to (1/6-x) . 2/3 = 3-2/3`
`to (1/6-x) . 2/3 = 7/3`
`to 1/6-x = 7/3 : 2/3`
`to 1/6-x = 7/2`
`to x = 1/6 - 7/2`
`to x = -10/3`
Vậy `x = -10/3`