If n is odd then its cube is also odd because odd times odd is odd. When we add 5, an odd number, we get an even number.
If n is even, its cube is also even so adding an odd number makes the sum odd. So if the expression is odd, n must be even.
Y=90x+2,000
90 is the rate of change because the hot air balloon descends 90 feet per minute.
And 2,000 is the starting point because the hot air balloon started the descent at 2,000 feet.
