Best to factor 5 out of the first 2 terms:
5x^2-7x+2=0 => <span>5(x^2 - [7/5]x) +2=0
Take half of [-7/5]: That'd be -7/10.
Square 7/10, add it to </span>5(x^2 - [7/5]x) +2=0 and then subtract it:
5(x^2 - [7/5]x)+ 49/100 - 49/100 ) +2=0
Then we have 5(x- [7/10] )^2 - 49/100 ) + 200/100 = 0
5(x-7/5)^2 - 245/100 + 200/100 = 0
5(x-7/5)^2 - 45/100 = 0
Dividing all terms by 5, x-7/5 = plus or minus sqrt( 9/100 )
x-7/5 = plus or minus 3/10
Then one root is x = 7/5 + 3/10, or x= 17/10 (answer #1)
The other is x = 7/5 - 3/10, or x = 14/10 - 3/10, or x = 7/10 (answer #2)
Answer: The average age is 7.1 years.
This problem is an example of when we need to take a weighted average. We simply can't just find the average of 5 and 8, because there are different children of each each.
To start, lets multiply the total number of children by their individual ages.
6 x 5 = 30 years
14 x 8 = 112 years
There are 142 years among the 20 years, so divide 142 by 20. This gives us an average age of 7.1 years.
Answer:
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Step-by-step explanation:
Answer:
I getting the probability of the adult female that will rent the action movies in DVDs in by dividing the possible probability outcome which is 10% of all adults by the total number of possible outcome. So all of the population of the female is 51% and the ones who rent is only 10%. the probability is 19%
