Amy would have spent $22.5 on her books (assuming you meant $10 total, not $10 per book)
A word to the wise: It's <span> f(x)=125(0.9)^x, where ^ represents exponentiation.
In this case the ave. value over the interval [11, 15] is
125(0.9)^15 - 125(0.9)^11
------------------------------------- = (125/4) [ 0.9^15 - 0.9^11)
15 - 11 = (31.25) [ 0.2059 - 0.3138 ] = a negative result
= (31.25)(-0.1079) = -3.372 (av. r. of c.
over the interval [11,15] )
Do the same thing for the time interval [1,5]. Then compare the two rates of change.</span>
Answer:
3/4 or 0.75
Step-by-step explanation:
The function for the monthly charge for water service would be
F(x) = 32 + 6.53x where x=the number of kilogallons used.
