Question

The formulas
Cgas=12,000+700x
Csolar+30,000+150x

model the total cost, in dollar, for gas and solar heating systems x years after installation. What is the ratio of the total cost for gas heating to the total cost for solar heating 5 year after installation? What is this ratio 40 years after installation?

Answer 1

would you like ratios in
A:B
or
\[\frac{A}{B}\]
form?

Answer 2

Yes, please agreena.

Answer 3

I guess it doesnt really matter, lol.

for the first case sub in 5 for x and evaluate:
12,000+700(5) = A = 15500
30,000+150(5) = B = 30750
Ratios then being
15500:30750
or
\[\frac{15500}{30750}=\frac{62}{123}\]

For the second set of ratios, plug in x=40 and evaluate.

Answer 4

Thank you very much agreena. :)