Popmarsid
Answered

How many terms are there in arithmetic sequence with a common difference of 4 and with first and last terms 3 and 59, respectively?

Sagot :

Mlcparra16id
The formula is:
[tex]n= \frac{a_n-a_1}{d} +1= \frac{59-3}{4} +1= \frac{56}{4} +1=14+1=15[/tex]

So there are 15 terms.
Jeremiaid
Formula:
               [tex] t_{n} = t_{1} + (n-1)d[/tex]

59 = [tex] t_{n} [/tex] - the nth term or could be the last term 
 3 = [tex] t_{1} [/tex] - the first term      
 4 = d - the common difference
 ? = n - the number of terms, the one we are solving for
(Substitute)

 [tex] t_{n} = t_{1} + (n-1)d[/tex]

59 = 3 + (n -1) 4
59 = 3 + 4n - 4
59 = 4n -1
59 + 1 = 4n
60 = 4n
60 / 4 = 4n /4
15 = n

So, n = 15.

There are 15 terms in the sequence.