Answer: B, C, E
-------
The difference between consecutive terms (numbers that come after each other) in arithmetic sequences is the same. That means you add the same number every time to get the next number. To figure out which choices are arithmetic sequences, just see if the differences are the same.
Choice A) 1, -2, 3, -4, 5, ...
-2 - 1 = -3
3 - (-2) = 5
The difference is not constant, so it is not an arithmetic sequence.
Choice B) 12,345, 12,346, 12,347, 12,348, 12,349, ...
12,346 - 12,345 = 1
12,347 - 12,346 = 1
The difference is constant, so it is an arithmetic sequence.
Choice C) <span>154, 171, 188, 205, 222, ...
171 - 154 = 17
188 - 171 = 17
The difference is constant, so it is an arithmetic sequence.
Choice D) </span><span>1, 8, 16, 24, 32, ...
8 - 1 = 7
16 - 8 = 8
</span>The difference is not constant, so it is not an arithmetic sequence.
Choice E) <span>-3, -10, -17, -24, -31, ...
-10 - (-3) = -7
-17 - (-10) = -7
</span>The difference is constant, so it is an arithmetic sequence.
Answer:
3. angles forming a linear pair to sum to 180
4. Def of supplementary angles
