Not sure why such an old question is showing up on my feed...
Anyway, let

and

. Then we want to find the exact value of

.
Use the angle difference identity:

and right away we find

. By the Pythagorean theorem, we also find

. (Actually, this could potentially be negative, but let's assume all angles are in the first quadrant for convenience.)
Meanwhile, if

, then (by Pythagorean theorem)

, so

. And from this,

.
So,
Amount saved:50I60I70l80l AND ON......
......weeks......:0..I1...l2..l3..l ..........AND ON
amount saved =x
weeks=y
after every y+10=x
60% - 3/5
Hope this help, don't really know what your expecting the answer to be
Answer:
I don't know
Step-by-step explanation:
I don't understand the point of this probem. It says that she has 35 envelopes best it doen't say how much can fit into each one. Maybe you ftogot some details pls reply in the comments.