18 * 5 = 90
90 represents 100%, because there are 5 20% in 100%
In total there are 90 club members
80% = 71 do not have birthdays in the summer.
The answer is 28 for this equation
First, enter the variables into the expression.
Square 1/3 and -6 to get this:

Divide 36 by 2/3:

Subtract 54 from1/9 to get the final answer:

, which is option D.
Hope this helps!
If I said I had .25 cents you would know I had a quarter of a dollar or 1/4th of a dollar, .25 cents could also be thought of as 25% of a dollar.
so in this case if the "dollar" is x and the "quarter" is .88 you could say you have 88% of x