How can i solve this math problem? (sequence question)?

Question

4, 7, 3, 4, ...

In the sequence above, the first term is 4, the second term is 7, and each term after the second term is the nonnegative difference between the previous two terms. if the "n"th term is the first term of the sequence that is equal to zero, what is the value of n?

i need help on this question...its on my PSAT practice test

Thank you for helping

Answer 1

The easiest and quickest way is to write down the sequence until you get a zero:

4, 7, 3, 4...

the fifth term is | 3- 4| = 1

the sixth is |4-1|=3

the seventh: |1-3|=2

the eighth: |3-2| = 1

the ninth: |2-1|=1

the tenth: |1-1| =0

so, the answer is n=10

Answer 2

Here is the full sequence:

4,7,3,4,1,3,2,1,1,0

if the "n"th term is the first term of the sequence "that is equal to zero", what is the value of n? 0

Answer 3

1 i think. 4-3-1-2-1-1-0