Answer:
In the given circle, segments OA, OB, OC and OD are radius of the circle.
In other words, all those segments are congruent.
From that we can deduct that triangles OAB and OCD are isosceles triangles, because all segments are equal. That makes those triangles congruent, because they have the same sides.
From the congruence we can deduct that all corresponding internal angles inside those triangles are actually congruent, that's why angle OAB and ODC must be congruent.
Also, angles DOC and BOA are also congruent, which means their subtended arcs are also congruent, because they have the same radius, so mAB = mCD.
You just have to rearrange the formula.
So:
765 = 135 x m + 225
765 - 225 = 135 x m
540 = 135 x m
m = 540 / 135
m = 4
So four months.
B.
It says x = y + 3. So what they did was put y + 3 in the place of x.
The y intercept is 5, since slope is y=mx+b. The x intercept is at -2. If you have more problems like this there is an amazing calculator that graphs equations like this for you. www.symbolab.com. Hope this helps!