(x+3)/0.2 - (0.4x-1)/0.5 = - 2.5
去分母 得
5(x+3) - 2(0.4x-1) = - 2.5
去括号 得
5x + 15 - 0.8x + 2 = - 2.5
4.2x = - 19.5
x = - 65/14