Đáp án + Giải thích các bước giải:
d, `2/3 x + 1/4 = 7/12`
` 2/3 x = 7/12 - 1/4`
` 2/3 x = 7/12 - 3/12`
` 2/3 x = 1/3`
` x = 1/3 : 2/3`
` x = 1/2`
Vậy `x = 1/2`
e, `3/5 x - 1/2 = 1/7`
` 3/5 x = 1/7 + 1/2`
` 3/5 x = 2/14 + 7/14`
` 3/5 x = 9/14`
` x = 9/14 : 3/5`
` x = 15/14`
Vậy `x = 15/14`
f, `1/4 + 1/3 : 3x = -5`
` 1/3 : 3x = -5 - 1/4`
` 1/3 : 3x = -20/4 - 1/4`
` 1/3 : 3x = -21/4`
` 3x = 1/3 : -21/4`
` 3x = -4/63`
` x = -4/63 : 3`
` x = -4/189`
Vậy `x = -4/189`
g, `1/4 + 1/3 : 3x = -5`
` 1/3 : 3x = -5 - 1/4`
` 1/3 : 3x = -20/4 - 1/4`
` 1/3 : 3x = -21/4`
` 3x = 1/3 : -21/4`
` 3x = -4/63`
` x = -4/63 : 3`
` x = -4/189`
Vậy `x = -4/189`
h, `1 - (5 3/8 + x - 7 5/24) : (-16 2/3) = 0`
` ( 5 9/24 + x - 7 5/24) : (-50/3) = 1 - 0`
` ( 5 9/24 + x - 6 29/24) : (-50/3) = 1`
` ( x - 11/6) : (-50/3) = 1`
` x - 11/6 = 1 . (-50)/3`
` x - 11/6 = -50/3`
` x = -50/3 + 11/6`
` x = -100/6 + 11/6`
` x = -89/6`
Vậy `x =-89/6`
