Answer:
Step-by-step explanation:
Given;
x² - 2x - 1 = 0
Solve by completing the square method;
⇒ take the constant to the right hand side of the equation.
x² - 2x = 1
⇒ take half of coefficient of x = ¹/₂ x -2 = -1
⇒ square half of coefficient of x and add it to the both sides of the equation
⇒ take the square root of both sides;
Therefore, option B is the right solution.
The expressions that could represent how much Leila pays in total for the model
\dfrac{107}{100}x
100 107 Option A is correct.
This is further explained below.
<h3>Which of the following expressions could represent how much Leila pays in total for the model?</h3>The price of the model is x
Now we are given that she also has to pay a 7 tax.
Amount of tax =7 % x
the Total cost
In conclusion, the statement might signify Leila's overall cost for the model.
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Let be the population mean lifetime of circulated $1 bills.
By considering the given information , we have :-
Since the alternative hypotheses is two tailed so the test is a two tailed test.
We assume that the lifetime of circulated $1 bills is normally distributed.
Given : Sample size : n=50 , which is greater than 30 .
It means the sample is large so we use z-test.
Sample mean :
Standard deviation :
Test statistic for population mean :-
The p-value=
Since the p-value (0.0433834) is greater than the significance level (0.02) , so we do not reject the null hypothesis.
Hence, we conclude that we do not have enough evidence to support the alternative hypothesis that the average lifetime of a circulated $1 bill differs from 18 months.