The arithmetic sequences 1, 5, 9, 13, ... and 1, 8, 15, 22, ... have infinitely many terms in common. Calculate the sum of the first three common terms.

87

Step-by-step explanation:

Sequence 1 has common difference of 4 and sequence 2 has 7

The first terms are common

We need a new sequence with common difference of:

LCM (4,7) = 4*7=28

So the next common term is 1+28 = 29 and the following one is 29+28 = 57

Sum of 3 terms:

1+29+57 = 87

15

24

Step-by-step explanation:

The first three common terms are:

1, 5, and 9.

1, 8, and 15.

Add them to find the sum.

1 + 5 + 9 = 15

1 + 8 + 15 = 24