Answer:
A. no solution
Step-by-step explanation:
We can use the second expression to substitute for y in the first expression. Then we have ...
1/2x +11 = -7x^2 -9x +6
Subtracting the right side, we get
7x^2 +(9 1/2)x +5 = 0
Eliminating fractions by multiplying by 2, this is ...
14x^2 +19x +10 = 0
The discriminant of this equation will tell the number and kind of roots. For a=14, b=19, c=10, the discriminant is ...
b^ -4ac = 19^2 -4·14·10 = 361 - 560 = -199
Since this value is negative, we know the two roots to the quadratic will be complex. There are no real solutions.
The graph in the attachment shows the two curves do not intersect, hence there are no values of x that will make the y-values match.
Answer:
Step-by-step explanation:
We can use the second expression to substitute for y in the first expression. Then we have ...
... 1/2x +11 = -7x^2 -9x +6
Subtracting the right side, we get
... 7x^2 +(9 1/2)x +5 = 0
Eliminating fractions by multiplying by 2, this is ...
... 14x^2 +19x +10 = 0
The discriminant of this equation will tell the number and kind of roots. For a=14, b=19, c=10, the discriminant is ...
... b^ -4ac = 19^2 -4·14·10 = 361 - 560 = -199
Since this value is negative, we know the two roots to the quadratic will be complex. There are no real solutions.
_____
The graph shows the two curves do not intersect, hence there are no values of x that will make the y-values match.
Answer:
The probability of an eighth grader winning is 1/3
Step-by-step explanation:
Total no. of students = 42
Number of students in 7th grade = 21
Number of students in 8th grade = 14
Number of students in 9th grade = 7
Probability of event =
So,the probability of an eighth grader winning=
Hence The probability of an eighth grader winning is 1/3
Answer:
Lower limit: 113.28
Upper limit: 126.72
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
Middle 60%
So it goes from X when Z has a pvalue of 0.5 - 0.6/2 = 0.2 to X when Z has a pvalue of 0.5 + 0.6/2 = 0.8
Lower limit
X when Z has a pvalue of 0.20. So X when
Upper limit
X when Z has a pvalue of 0.80. So X when