The ninth grade class has a total of 450 students made up of x girls and y The number of girls minus twice the number of boys is 18. Find the number of girls are in the ninth grade. Which system of equations and solution represent this situation?

Multiple choice question.
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A)
x+y=450 and x−2y=18 ; There are 234 girls in the ninth grade.

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B)
x+y=450 and x−2y=18 ; There are 306 girls in the ninth grade.

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C)
x+y=450 and 2x−y=18 ; There are 156 girls in the ninth grade.

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D)
x−y=18 and 2x−y=18 ; There are 162 girls in the ninth grade.

the equation for this situation is y=122+45. to solve the equation you would add 45 and 122 to get a total of 167lbs. in conclusion, grace's weight eight weeks ago was 167lbs.  

30

step-by-step explanation:

times by times

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;

5

step-by-step explanation: