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:
m∠7=34°
Step-by-step explanation:
m∠2=m∠8=146° because alternate interior angles are congruent.
m∠7=180-m∠8=34° because it is a linear pair.
Factor strings for 36:
6 x 6
2 x 18
3 x 12
4 x 9
2 x 2 x 3 x 3
2 x 2 x 9
4 x 3 x 3
6 x 2 x 3
Hope that helped :D
Step-by-step explanation:
Angle A = 4x + 12 = 4(15) + 12 = 72°.
Acute is for angles that are less than 90°.
Obtuse is for angles that are between 90° and 180°, not inclusive.
Right is for angles that are 90°
Hence the answer is acute.