What are the roots of the equation? 2x^2+x=6
2 answers:
Answer:
x = - 2, x =
Step-by-step explanation:
Given
2x² + x = 6 ( subtract 6 from both sides )
2x² + x - 6 = 0
Consider the factors of the product of the x² term and the constant term which sum to give the coefficient of the x- term.
product = 2 × - 6 = - 12 and sum = + 1
The factors are + 4 and - 3
Use these factors to split the x- term
2x² + 4x - 3x - 6 = 0 ( factor the first/second and third/fourth terms )
2x(x + 2) - 3(x + 2) = 0 ← factor out (x + 2) from each term
(x + 2)(2x - 3) = 0
Equate each factor to zero and solve for x
x + 2 = 0 ⇒ x = - 2
2x - 3 = 0 ⇒ 2x = 3 ⇒ x =
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Answer:
We are 95% confident that the percent of executives who prefer trucks is between 19.43% and 33.06%
Step-by-step explanation:
We are given that in a group of randomly selected adults, 160 identified themselves as executives.
n = 160
Also we are given that 42 of executives preferred trucks.
So the proportion of executives who prefer trucks is given by
p = 42/160
p = 0.2625
We are asked to find the 95% confidence interval for the percent of executives who prefer trucks.
We can use normal distribution for this problem if the following conditions are satisfied.
n×p ≥ 10
160×0.2625 ≥ 10
42 ≥ 10 (satisfied)
n×(1 - p) ≥ 10
160×(1 - 0.2625) ≥ 10
118 ≥ 10 (satisfied)
The required confidence interval is given by
Where p is the proportion of executives who prefer trucks, n is the number of executives and z is the z-score corresponding to the confidence level of 95%.
Form the z-table, the z-score corresponding to the confidence level of 95% is 1.96
Therefore, we are 95% confident that the percent of executives who prefer trucks is between 19.43% and 33.06%