Answer:
4th term
Step-by-step explanation:
Equate the nth term formula to 54 and solve for n
3n² - n + 10 = 54 ( subtract 54 from both sides )
3n² - n - 44 = 0
Consider the factors of the product of the n² term and the constant term which sum to give the coefficient of the n- term.
product = 3 × - 44 = - 132 and sum = - 1
The factors are - 12 and + 11
Use these factors to split the n- term
3n² - 12n + 11n - 44 = 0 ( factor the first/second and third/fourth terms )
3n(n - 4) + 11(n - 4) = 0 ← factor out (n - 4) from each term
(n - 4)(3n + 11) = 0
Equate each factor to zero and solve for n
n - 4 = 0 ⇒ n = 4
3n + 11 = 0 ⇒ 3n = - 11 ⇒ n = - [tex]\frac{11}{3}[/tex]
Since n > 0 then n = 4
