<em>Answer : C: $125.</em>
Hopefully that helps you ! have a good day !
Hello!

Recall that:
can be rewritten as:

Use the equation for the derivative of a log expression:

Substitute in the values in the expression:

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
7 will never equal 8 so there is no solution. so i think it is C
Area = side * side
Area of the square = 6 1/9 * 6/1/9
= 36 1/81