Absolute value equations have more than one solution because when the answer is in abs. value, it is positive, so there could be a negative answer and it would still be positive. For example |-5|=5 and |5|=5 as well.
4+|2x|=-1 would have no solution because you cannot have the equation equal a negative since the 2x is in absolute value.
30% because 10 out of 10 is 100%.
So 3 out of 10 is 30%.
