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)
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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:
just do 21/25
Step-by-step explanation:
Answer:
2x+50 and 5x-55 both are congruent or have same measure.
Step-by-step explanation:
Since we want to prove that both lines are parallel, this means no theorems that involve with parallel lines apply here.
First of, we know that AC is a straight line and has a measure as 180° via straight angle.
x+25 and 2x+50 are supplementary which means they both add up to 180°.
Sum of two measures form a straight line which has 180°.
Therefore:-
x+25+2x+50=180
Combine like terms:-
3x+75=180
Subtract 75 both sides:-
3x+75-75=180-75
3x=105
Divide both sides by 3.
x=35°
Thus, x = 35°
Then we substitute x = 35 in every angles/measures.
x+25 = 35°+25° = 60°
2x+50 = 2(35°)+50° = 70°+50° = 120°
5x-55 = 5(35°)-55 = 175°-55° = 120°
Since 2x+50 and 5x-55 have same measure or are congruent, this proves that both lines are parallel.
