Hi there, we use PEMDAS to solve this problem, PEMDAS is parenthesis, Exponents, Multiply, Divide, Add, and Subtract. In this case, we have [6.6÷(-5+3)]*(-1), 6.6/-5+3(-1)=6.6/-2(-1)=(-3.3)(-1)=3.3. So, your answer is 3.3
Experimental probability is if an experiment was actually run. If those values are the result of an experiment, then the probability is desired value (white) over total possibilities.

or 0.6
Subtract 18 from 72 to get Michelle's current age.
72 - 18 = 54