Answer:
61
Step-by-step explanation:
As x goes from 1 to 2, y increases by 3 from 4 to 7
As x goes from 2 to 3, y increases by 3 from 7 to 10
We increase by 3 each time x increases by 1
The formula for an arithmetic sequence is
an = a1+d(n-1)
where a1 is the first term which is 4
d is the common difference or the number we add each time which is 3
n is the term we are looking for which is 20
a20 = 4 +3 (20-1)
a20 = 4+3*19
a20 = 4+57
= 61
