Answer:


Step-by-step explanation:
we know that
The number of kWh of energy that the model house generate per year is given by the sum of kWh of energy generates by the windmills multiplied by the number of windmills, plus the kWh of energy generates by the solar panels multiplied by the number of solar panels.
so

For 10 year
Multiply the expression above by 10

Apply distributive property

Answer:
$12159 per year.
Step-by-step explanation:
If I invest $x each year at the simple interest of 7.5%, then the first $x will grow for 35 years, the second $x will grow for 34 years and so on.
So, the total amount that will grow after 35 years by investing $x at the start of each year at the rate of 7.5% simple interest will be given by

= ![35x + \frac{x \times 7.5}{100} [35 + 34 + 33 + ......... + 1]](https://tex.z-dn.net/?f=35x%20%2B%20%5Cfrac%7Bx%20%5Ctimes%207.5%7D%7B100%7D%20%5B35%20%2B%2034%20%2B%2033%20%2B%20.........%20%2B%201%5D)
= ![35x + \frac{x \times 7.5}{100} [\frac{1}{2} (35) (35 + 1)]](https://tex.z-dn.net/?f=35x%20%2B%20%5Cfrac%7Bx%20%5Ctimes%207.5%7D%7B100%7D%20%5B%5Cfrac%7B1%7D%7B2%7D%20%2835%29%20%2835%20%2B%201%29%5D)
{Since sum of n natural numbers is given by
}
= 35x + 47.25x
= 82.25x
Now, given that the final amount will be i million dollars = $1000000
So, 82.25x = 1000000
⇒ x = $12,158. 05 ≈ $12159
Therefore. I have to invest $12159 per year. (Answer)
.50 is the answer I think, hope this helps