Let

where we assume |r| < 1. Multiplying on both sides by r gives

and subtracting this from
gives

As n → ∞, the exponential term will converge to 0, and the partial sums
will converge to

Now, we're given


We must have |r| < 1 since both sums converge, so


Solving for r by substitution, we have


Recalling the difference of squares identity, we have

We've already confirmed r ≠ 1, so we can simplify this to

It follows that

and so the sum we want is

which doesn't appear to be either of the given answer choices. Are you sure there isn't a typo somewhere?
Answer:
500
Step-by-step explanation:
Let the unknown number be n. Then 1.5n = 750, and n = 500.
750 is 150 percent of 500.
A $20 decrease followed by a $20 increase - original value
A 75% decrease followed by a 50% increase - less than the original value
A 50% increase followed by a 33 1/3% decrease - greater than the original value
A 60% increase followed by a 40% decrease - greater than the original value
A 100% increase followed by a 33 1/3% decrease - greater than the original
AOB = 2 . x
2x = 60°
x = 30°
Answer:
Step-by-step explanation:21