Step-by-step explanation:
the average rate of change of a function f in an interval [x-low, x-high] is
(f(x-high) - f(x-low)) / (x-high - x-low)
the year 2000 means t = 2000-1980 = 20
the year 2015 means t = 2015-1980 = 35
so, we have
(A(35) - A(20)) / (35 - 20)
((-0.6(35)² + 37.2×35 + 243) - (-0.6(20)² + 37.2×20 + 243)) / 15
((-735 + 1302 + 243) - (-240 + 744 + 243)) / 15
(810 - 747) / 15 = 63/15 = 4.2
the average change rate between 2000 and 2015 is 4.2.
that means that the use of nuclear energy in the USA increased by 4.2 billions of kilowatt hours per year during that period.
The original price of the item will be $ 480.When there is 75% off on the original price.
<h3>What is the percentage?</h3>
The quantity of anything is stated as though it were a fraction of a hundred. A fraction of 100 can be used to express the ratio.
The right question is
"Joyce saved $120 on an item that was 75 % off. What was the original price?"
Given data;
% off = 75
Amount saved $120
Let the original price of the item is x
75 % of x + $120 = x
0.75x+ 120 =x
0.25 x =120
x=120/0.25
x=480
Hence, the original price of the item will be $ 480.
To learn more about percentages, refer to:
brainly.com/question/13450942
#SPJ1
Angle four is 30° and angle 7 is 150! angle four equals 30° because a straight line equals 180, and 180-150=30. angle 7 is 150 through corresponding angles
Answer:
21
Step-by-step explanation:
Let x = the number
12x-12 = 240
12x = 252
x = 21
