Answer:
The difference between the 4th term of both series is 7
Explanation:
The formula for the nth term of an APS is a + (n - 1)×d
The first term of one of the series = -1
The first term of the other of the series = -8
The fourth term of both series is thus;
4th term first series = -1 + (4 - 1)× d = -1 + 3·d
4th term second series = -8 + (4 - 1)× d = -8 + 3·d
The difference between the 4th term of both series = -1 + 3·d - (-8 + 3·d)
-1 + 3·d - (-8 + 3·d) = -1 + 3·d + 8 - 3·d = 8 - 1 = 7
The difference between the 4th term of both series = 7.