13/20,3/5,29/50,14/25,53/100
2 + 4(3+2x) = 3x + 8
2 + 12 + 8x = 3x + 8
14 - 8 = 3x - 8x
6 = -5x
x = -6/5
-5.9, -4.6, -1/4, 1/2, 1.75, 2, 18, 21.
<span>Let a_0 = 100, the first payment. Every subsequent payment is the prior payment, times 1.1. In order to represent that, let a_n be the term in question. The term before it is a_n-1. So a_n = 1.1 * a_n-1. This means that a_19 = 1.1*a_18, a_18 = 1.1*a_17, etc. To find the sum of your first 20 payments, this sum is equal to a_0+a_1+a_2+...+a_19. a_1 = 1.1*a_0, so a_2 = 1.1*(1.1*a_0) = (1.1)^2 * a_0, a_3 = 1.1*a_2 = (1.1)^3*a_3, and so on. So the sum can be reduced to S = a_0 * (1+ 1.1 + 1.1^2 + 1.1^3 + ... + 1.1^19) which is approximately $5727.50</span>
Answer:
Step-by-step explanation:
Set up a proportion.
3/25 = x / 20 Notice that both times are in the denominators. Be sure you always set up a proportion that way. Like units in the denominator. Like units in the numerator.
Cross multiply
3 * 20 = 25 * x Combine
60 = 25x Divide by 25
60/25 = x
x = 2.4 miles in 20 minutes.
