Answer:
10 terms
Step-by-step explanation:
equate the sum formula to 55 and solve for n
n(n + 1) = 55 ( multiply both sides by 2 to clear the fraction )
n(n + 1) = 110 ← distribute parenthesis on left side
n² + n = 110 ( subtract 110 from both sides )
n² + n - 110 = 0 ← in standard form
Consider the factors of the constant term (- 110) which sum to give the coefficient of the n- term (+ 1)
the factors are + 11 and - 10 , since
11 × - 10 = - 110 and 11 - 10 = + 1 , then
(n + 11)(n - 10) = 0 ← in factored form
equate each factor to zero and solve for n
n + 11 = 0 ⇒ n = - 11
n - 10 = 0 ⇒ n = 10
However, n > 0 , then n = 10
number of terms which sum to 55 is 10
-2x^2(4x − 3)
=-8x^3 + 6x^2
hope it helps
Without the discount each book is 16.25 with the discount theyre 15 each
Answer: They cost the same amount.
Step-by-step explanation:
35(0.20)=7
35-7=28
40(0.30)=12
40-12=28
28=28
Answer:
The 99% confidence interval is 
Step-by-step explanation:
From the question we are told that
The sample size is 
The sample mean is 
The standard deviation is 
Given that confidence is 99% then the level of significance is mathematically represented as
Next we obtain the critical values of 
from the normal distribution table
The value is
Generally the margin for error is mathematically represented as
=> 
=> 
The 99% confidence interval is mathematically represented as
=> 
=>
