Đáp án:
Bài 1
a)
` x - 3/4 = 1/7`
` x = 1/7 + 3/4`
` x = 25/28`
b)
` (-x +3/5) + 13/20 = 5/6
` -x + 3/5 = 11/60`
` -x = -5/12`
` x = 5/12`
c)
` x/2 - 2/5 = 1/10`
` x /2 = 1/2`
` x = 1`
Bài `2`
a)
` => |x| = 4/15 + 7/6`
` => |x| = 43/30`
` => x = ± 43/30`
b)
TH1
` x - 4/3 = 1/6`
` => x = 1/6 + 4/3`
` x = 3/2`
TH2
` x - 4/3 = -1/6`
` x = -1/6 +4/3`
` x = 7/6`
c)
` => | x -4/3| =1/3 +1/2`
` => |x-4/3| = 5/6`
TH1
` x -4/3 = 5/6`
` x = 5/6 +4/3`
` x = 13/6`
`TH2`
` x -4/3 = -5/6`
` x = -5/6 +4/3`
` x = 1/2`
d)
` =>~ |7/9 - x| = 8/3 + 1/5 = 43/15`
TH1
` 7/9 - x = 43/15`
` x = 7/9 - 43/15`
` x = -94/45`
TH2
` 7/9 - x = -43/15`
` x = 7/9 + 43/15 = 164/45`