Answer:
x = 5
y = 0
Step-by-step explanation:
3x + y = 15
3x -y = 15
Add the two equations;
6x = 30
Inverse operations;
6x = 30
/6 /6
x = 5
Back substitute;
3(5) + y = 15
15 + y = 15
y = 0
The <em><u>correct answer</u></em> is:
We can conclude that 68% of the scores were between 55 and 85; 95% of the scores were between 40 and 100; and 99.7% of the scores were between 25 and 100.
Explanation:
The empirical rule tells us that in a normal curve, 68% of data lie within 1 standard deviation of the mean; 95% of data lie within 2 standard deviations of the mean; and 99.7% of data lie within 3 standard deviations of the mean.
The mean is 70 and the standard deviation is 15. This means 1 standard deviation below the mean is 70-15 = 55 and one standard deviation above the mean is 70+15 = 85. 68% of data will fall between these two scores.
2 standard deviations below the mean is 70-15(2) = 40 and two standard deviations above the mean is 70+15(2) = 100. 95% of data will fall between these two scores.
3 standard deviations below the mean is 70-15(3) = 25 and three standard deviations above the mean is 70+15(3) = 115. However, a student cannot score above 100%; this means 99.7% of data fall between 25 and 100.
Answer:
18x^2+6
Step-by-step explanation:
2(9x^2+3)
multiply each term in parentheses by 2
2 x 9x^2+2 x 3
calculate product
18x^2+2 x 3
multiply numbers
18x^2+6
1. 2 years
2. 35 days
3. 108 months
4. 2 weeks
5. 512 min
6. 7 weeks
7. 3 hours
8. 5 years
9. 63 days
10. 300 minutes
11. 180 months
12. 2400 minutes
13. 84 months
14. 42 days
15. 40 hours
I hope this helped I worked hard on this. c:
