-1, 4, 9 Determine the numerical position of the team 24

Answer 1

-1, 4, 9, 14, 19, 24, 29, 34, 39, ...

notice all the positive terms end in 4 or 9 as the last digit

24 is the 6th term, just count them

or maybe you want the 24th term:

an = a1 +d(n-1) = nth term, a1=-1, d=common difference =5

a1 = -1

an = -1 +5(n-1)

a24 = -1 +5(23) = -1 +115 = 114

= the 24th term

it's last digit is 4, so unlikely there's mistake in calculations

Answer 2

This is an arithmetic sequence considering the numbers increment by the same number each time. an=a1+(n-1)d is the key equation where d=common difference (5 in this case), a1=-1, and an=24.

Substituting and solving for "n" algebraically we have 24=-1+5(n-1)

Add one to each side: 25=5(n-1)

Divide by 5: 5=n-1

Add one to both sides: n=6. So it's the sixth term.

24 is not that far away. You can check by adding five each time and keeping count of the numerical position.