Question

The Reyes family decides to install expensive solar panels to replace their current energy source that uses fossil fuel. Presently, this switch to solar energy comes at a major financial cost. Why might the Reyes' decision be considered a wise one in 40 years?

Answer 1

Let's say that the cost of the solar panel installation is 12,500 and the Reyes family pays 200 a month for electricity. in 40 years the Reyes family would have saved a lot of money on electricity.

f(480)=200(480) - 12,500 

the Reyes family would save 

83,500$ in 40 years.