1. 1/3 + 1/2 : x = -4
=> 1/2 : x = -4 - 1/3
1/2 : x = -13/3
=> x = 1/2 : (-13/3)
x = -3/26
2. 3x - 30%.x = -5,4
3x - x = -18
2x = -18
=> x = -18 : 2
x = -9
3. x-43 = (57 - x) - 50
=> (57 - x) . (x - 43) = -50
=> 57 - x = -50 => x = 107
=> x - 43 = -50 => x = -50 + 43 = -7
4. 3/8 - 1/6x = 1/4
=> 1/6x = 3/8 - 1/4 = 1/8
=> x = 1/8 : 1/6 = 3/4
5. 2/3 + 1/3 : x = 3/5
=> 1/3 : x = 3/5 - 2/3 = -1/15
=> x = 1/3 : (-1/15) = -5
6. x + 30%x = -1/3
bó tay hihi!!!!