Solve by factoring
2 answers:
Answer:
A
Step-by-step explanation:
Given
4m² - 31m - 45 = 0
Consider the factors of the product of the coefficient of the m² term and the constant term which sum to give the coefficient of the m- term
product = 4 × - 45 = - 180 and sum = - 31
The factors are - 36 and + 5
Use these factors to split the m- term
4m² - 36m + 5m - 45 = 0 ( factor the first/second and third/fourth terms )
4m(m - 9) + 5(m - 9) = 0 ← factor out (m - 9) from each term
(m - 9)(4m + 5) = 0
Equate each factor to zero and solve for m
m - 9 = 0 ⇒ m = 9
4m + 5 = 0 ⇒ 4m = - 5 ⇒ m = -
You might be interested in
Answer: 95% confidence interval = 20,000 ± 2.12
( 19228.736 , 20771.263 ) OR ( 19229 , 20771 )
Step-by-step explanation:
Given :
Sample size(n) = 17
Sample mean = 20000
Sample standard deviation = 1,500
5% confidence
∴ = 0.025
Degree of freedom () = n-1 = 16
∵ Critical value at ( 0.025 , 16 ) = 2.12
∴ 95% confidence interval = mean ±
Critical value at 95% confidence interval = 20,000 ± 2.12
( 19228.736 , 20771.263 ) OR ( 19229 , 20771 )