Đáp án + Giải thích các bước giải:
`a)` `-2/3*x+1/5=3/10` $\\$ `=>-2/3*x=3/10-1/5=3/10-2/10=1/10` $\\$ `=> x = 1/10:(-2/3)` $\\$ `=> x = 1/10 * (-3/2) = -3/20`
Vậy `x = -3/20`
`b)` `-1/2 + 1/3 :x = 1` $\\$ `=> 1/3:x=1-(-1/2)` $\\$ `=> 1/3:x = 1 + 1/2 = 3/2` $\\$ `=> x = 1/3 : 3/2` $\\$ `=> x= 1/3 * 2/3 = 2/9`
Vậy `x = 2/9`
`c)` `2x - 1/4 = -1/2` $\\$ `=> 2x = -1/2 + 1/4` $\\$ `=> 2x = -1/4` $\\$ `=> x = (-1/4):2 =(-1/4)*1/2 = -1/8`
Vậy `x = -1/8`
`d)` `5 3/8 - 4/5(x-1)=4 3/8` $\\$ `=> 4/5(x-1)=5 3/8 - 4 3/8` $\\$ `=> 4/5(x - 1) = 1` $\\$ `=> x - 1 = 1 : 4/5` $\\$ `=> x - 1 = 1*5/4 = 5/4` $\\$ `=> x = 5/4 + 1` $\\$ `=> x = 5/4 + 4/4 = 9/4`
Vậy `x = 9/4`
