Answer: 1/10
Answer step by step:
1) 3x - 4/5 = - 1/2
2) 3x = -1/2 + 4/5 (move -4/5 to the right side of the equation and inverse the negative sign)
3) 3x = 0.3 (add the values)
4) 3x / 3 = 0.3 / 3 (divide both side with 3 to get rid of the constant value)
5) x = 0.1
6) x = 1/10 (the 1 in 0.1 is in the tenth place so we convert it to 1/10)