Answer:
see below
Step-by-step explanation:
The formula for the sum of an infinite geometric series with first term a1 and common ratio r (where |r| < 1) is ...
sum = a1/(1 -r)
Applying this to the given series, we get ...
a. sum = 5/(1 -3/4) = 5/(1/4) = 20
b. sum = d/(1 -1/t) = d/((t-1)/t) = dt/(t-1)
_____
The derivation of the above formula is in most texts on sequences and series. In general, you write an expression for the difference of the sum (S) and the product r·S. You find all terms of the series cancel except the first and last, and the last goes to zero in the limit, because r^∞ → 0 for |r| < 1. Hence you get ...
S -rS = a1
S = a1/(1 -r)
Answer:
2.55
Step-by-step explanation:1
Convert 1121\frac{1}{2}121 to improper fraction. Use this rule: abc=ac+bca \frac{b}{c}=\frac{ac+b}{c}acb=cac+b.
34+3.3−1×2+12\frac{3}{4}+3.3-\frac{1\times 2+1}{2}43+3.3−21×2+1
2
Simplify 1×21\times 21×2 to 222.
34+3.3−2+12\frac{3}{4}+3.3-\frac{2+1}{2}43+3.3−22+1
3
Simplify 2+12+12+1 to 333.
34+3.3−32\frac{3}{4}+3.3-\frac{3}{2}43+3.3−23
4
Simplify.
5.12\frac{5.1}{2}25.1
5
Simplify.
2.552.552.55
The first thing we must do for this case is to take into account the following variable:
x = speed in miles per hour
Then, by definition we have to:
d = v * t
Where,
d: distance
v: speed
t: time
Substituting values:
250 = x * 5
Answer:
An equation that can be used to find the speed of the train is:
250 = x * 5
7.63 ^-10!!!!!!!!!!!!!!!!!!!!!!!!