For combining like terms: it is 7z
Using PEMDAS
(Parenthesis)(Exponents)(Multiplication/Division)(Addition/Subtration)
So:


The third angle is 60 degrees. A triangle has 180 degrees so 180-30-90=60
May has 31 days
31 x 24 = 744 hours in may
744 x 40 = 29760 watt hours
29760 watt hours = 29.76 kwh
29.76 x 75 = 2232 cents
2232 cents = $22.32
The domain and the range is [-6 to +inf)