-1 - (-7) = 6
5 - (-1) = 6
11 - 5 = 6
The common difference is 6.
If you add 6 to a term, you get the next term.

Answer:
C
Step-by-step explanation:
-1.5x=-2.55
1.5x=2.55
x=2.55/1.5
x=1.7
I think it’s the maximum number of solutions is one
Answer:
A
Step-by-step explanation:
Answer:
39°
Step-by-step explanation:
A radius of a circle (segment CD) drawn to the point of tangency (D) intersects the tangent (line DE) at a 90-deg angle.
That makes m<D = 90.
m<D + m<C + m<E = 180
90 + 51 + m<E = 180
m<E = 39