Answer:
r = 4/5
Step-by-step explanation:
Formula
Sum of an infinite geometric series = a / (1 - r)
Givens
Sum = 5*a
a = a
r = ?
Solution
5a = a/(1 - r) Divide both sides by a
5a/a = a / (a * (1 - r) The a's on the right cancel
5 = 1 / (1 - r) Multiply both sides by 1 - r
5*(1 - r) = 1*(1 - r)/(1 - r) The 1 - r s on the right cancel
5*(1 - r) = 1 Remove the brackets.
5 - 5r = 1 Subtract 5 from both sides
5-5 - 5r = 1 - 5 Combine
-5r = - 4 Divide by - 5
r = 4/5
Answer:
Step-by-step explanation:
First, you must find the actual decrease in temperature.
Decrease = Yesterday's temperature - Today's temperature
Decrease = 80 - 75
Decrease = 5 degrees
Now, find the percentage decrease.
% Decrease = Actual decrease / Yesterday's temperature x 100
% Decrease = 5/80 x 100
% Decrease = 0.0625 x 100
% Decrease = 6.25 %
So, the percent decrease in high temperature from yesterday to today is 6.25%
Answer:
5, 5, 10, 15
Step-by-step explanation:
He spent 1/4 of 20 which is 5 on food, 1/2 of 20 which is 10 on music, so if you add those you get 15. 20-15 is equal to 5.
