What value added to x2 + 2x would complete the square
2 answers:
Answer:
1 would complete the square
Step-by-step explanation:
In order to solve this you have to remember the formlua for the perfect quadratic trinomial:
IN the example you have A^2 and 2ab, since A=1, then the 2x will resulto from the multiplication of b and a multiplied by 2, so we just have to divide 2x by 2x to get b:
So we get that b is 1.
You might be interested in
Answer:
And we can find this probability with this difference:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the number of passengers who arrive at the platform of a population, and for this case we know the following info
Where and
We are interested on this probability
For this case we can assume that the random variable is normally distributed.
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability with this difference:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.