Answer:
x = -3/2 x=2
Step-by-step explanation:
2x² - x-6=0
Factor
(2x ) (x ) =0
6 = 2*3
2*-2 +3 = -1
(2x +3 ) (x -2 ) =0
2x+3 =0 x-2 =0
2x = -3 x=2
x = -3/2 x=2
Answer:
history test
Step-by-step explanation:
Problems of normally distributed samples can be 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:
He did better relative to the class in the test in which he had a higher Z score.
So:
History
Raul received a score of 75 on a history test for which the class mean was 70 with a standard deviation of 7. So we have 
So:



Biology
He received a score of 73 on a biology test for which the class mean was 70 with standard deviation 7. So we have 
So:



He had a higher Z score in the history test, so this is the test in which he did better relative to the rest of the class.
(3/5)b - 7 = a
Remember "of" means to multiply. Less than means subtraction: 7 less than means -7.
I believe it is 864, I'm not 100% sure. But I think it is.
The square number is 4 hence The answer is 4