Answer:
x=123
Step-by-step explanation:
x is across from the angle that measures 123 degrees. Therefore, they are vertical angles, and are congruent.
x=123
Additionally, 57 and x are on a straight line. This means they are supplementary and add to 180 degrees
57*x=180
Subtract 57 from both sides to get x by itself.
x=123
7-4=3
10-7=3
13-10=3
we can see that this is an arithmetic sequence with a difference of 3
the nth term=the first term +(n-1) times the difference
so a(n)=4+3(n-1)
