Let x = your number.
x^2 - 21 = 4x. Subtract 4x from both sides.
x^2 - 4x - 21 = 0. Factor.
(x - 7) (x + 3) = 0. Set each term to 0.
x + 3 = 0. Subtract 3 from both sides.
x = -3. This is the negative solution.
Set the other term equal to zero.
x - 7 = 0. Add 7 to each side.
x = 7. This is the positive solution.
Answer:
9-4t
Step-by-step explanation:
Answer:
The correct option is C:
C) The representative sample contained more girls than boys.
Step-by-step explanation:
It is given that a random sample is chosen from a total students of 160 students. The sample can be of 10,15 or any small numbers of students as compared to 160. However, a sample cannot be of 160 students as it is defined as a population in this case.
A random sample is always unbiased. Which means that the sample chosen should have around the same proportion of girls to boys as it is in the population of 160.
We know that:
Total boys in 160 = 65
Total girls in 160 = 95
Proportion of girls to boys = 95/65 = 1.462
Which means that for every 1 boy, there are 1.462 of girls.
The same ratio is held in a random sample, hence the total number of girls will be greater than boys
Hey there James!
So, just remember, 2/5 is almost half of 1.
When it is almost half of 1, this means that it would have to be 2.5/5
This would mean that 4/10 would be your answer, because it is almost half of 1 also.
Hope this helps.
Answer: 1 1/2
Step-by-step explanation: