The answer is -7 for sure
Ratio = 5:2:3:8
Sum of all internal angles = 360°
5x + 2x + 3x + 8x = 360°
18x = 360°
x = 20°
Therefore,
5x = 100°
2x = 40°
3x = 60°
8x = 160°
5:2:3:8 :: 100:40:60:160.
Answer:
The first term is 14.
Step-by-step explanation:
The general formula for this kind of sequence (arithmetic) is a(n) = a(1) + (n-1)c, where c is the common difference. Here, we have a(6) = -1 = a(1) + (6-1)(-3), or -1 +15 = a(1). The first term is 14.