Given
base=2x+6
height=x+4
and
area=56 square units
56=1/2 times (2x+6) times (x+4)
times bot sides by 2
112=(2x+6)(x+4)
expand
112=2x²+14x+24
divide both sides by 2
56=x²+7x+12
minus 56 both sides
0=x²+7x-44
factor
waht 2 numbers mulitply to get -44 and add to get 7
11 and -4
0=(x-4)(x+11)
set to 0
x-4=0
x=4
x+11=0
x=-11
false, measures can't be negative
x=4
height=x+4
height=4+4=8
base=2x+6
base=2(4)+6=8+6=14
x=4 and base=14 and height=8
1 and 17 are the only factors.
112-88 = 24
they save $24 per month
so 650/24 = 27.083
so it will pay for itself in 27.083 months, round up to 28 months
Answer: 
Explanation: Denominators of a fraction can be equivalently written as their value to the power of negative 1. In this case the denominator expression itself has an exponent of 6, which taken to the power of negative one becomes -6:
To do 130% increase you multiply by 1.3 so you do 810 × 1.3 = 1053
