Question

The algebra of sum of an arithmetic sequence is n² +4n.How many terms from the first are needed to get the sum 192?​

Answer 1

Answer:

number of terms = 12

Step-by-step explanation:

sum of the arithmetic sequence = n² + 4n

number of terms needed to get sum of 192

Sn = n² + 4n

192 = n² + 4n

n² + 4n - 192 = 0

n² + 16n - 12n - 192 = 0

n(n + 16) - 12(n + 16) = 0

(n + 16) (n - 12) = 0

n + 16 = 0 n - 12 = 0

n = - 16 n = 12

we take number of terms is 12

therefore the number of terms to get sum of 192 is 12

hope you get your answer