1. The first term is 7.....only one answer has a first term = 7
2.
8, 6, 4 , 2
The difference in the successive term to the previous term is -2
And the first term is 8
So we have
a1 = 8 , an = an-1 - 2 ⇒ first answer
3.
-3, 1, 5 ,9
an = -3 + 4(n - 1) ⇒ first answer
