`1)`
`a) 4/7 + 3/7 : (-3/2)`
`= 4/7 + (-2)/7`
`= 2/7`
``
`b) -7/15 + 1 2/5 - (-2/3)`
`= -7/15 + 7/5 + 2/3`
`= -7/15 + 21/15 + 10/15`
`= 8/5`
``
`c) -19/23 . 11/12 + (-4)/23 . 11/12`
`= (-19/23 + (-4)/23) . 11/12`
`= -1 . 11/12`
`= -11/12`
``
`d) (-2/5 + 3/8) : 4/5 + (-3/5 + 5/8) : 4/5`
`=(-2/5 + 3/8) . 5/4 + (-3/5 + 5/8) . 5/4`
`=[(-2/5 + 3/8) + (-3/5 + 5/8) ] . 5/4`
`= (-2/5 + 3/8 - 3/5 + 5/8) . 5/4`
`=[ (-2/5 - 3/5) + (3/8 + 5/8)] . 5/4`
`= [(-1) + 1] . 5/4`
`= 0 . 5/4`
`= 0`
``
`2)`
`0,5 + 2x = -3/2`
`2x = -3/2 - 0,5`
`2x = -2`
`x = -2 : 2`
`x = -1`
Vậy `x = -1`
``
`b)5/8x - 3/5 = -3/2`
`5/8x = -3/2 + 3/5`
`5/8x =-9/10`
`x = -9/10 : 5/8`
`x=-36/25`
Vậy `x = -36/25`
``
`c) 10/4 - ( x + 5/3) = 5/6`
`(x + 5/3) = 10/4 - 5/6`
`x + 5/3 = 5/3`
`x = 5/3 - 5/3`
`x = 0`
Vậy `x = 0`
`#caty09`
