% means out of 100 so 1%=1/100
so 3%=3/100
$30.00=3000 cents
so you multiply 3/100 by 3000 =(3*3000)/100
you can cross out two zeros at the bottom and on the top and get
(3*30)/1 or 90/1 or 90 cents
You turn an improper fraction to a decimal by dividing the numerator (number on top) by the denominator (number under).
The keyword is "sum" which tells you x, y, and z are being added. One half of the sum means that the sum of the three numbers is going to be divided by 2.
x + y + z
------------
2
Apply the "FOIL" method here. (m+1)(m+1) = m^2 + 1m + 1m + 1, or m^2 + 2m + 1.