Answer:
Alvin: 49
Elga: 40
Step-by-step explanation:
- The equation is 89 = x + (x-9).
- Remove the parenthesis and combine the like terms. 89 = 2x - 9
- Add 9 on both sides. 98 = 2x
- Divide by 2 on both sides. x = 49
- 49 is the age of Alvin. (49-9) 40 is the age of Elga.
Answer:
the answer is big and your dad knows the answer is B a use Desmos amen
Answer:
The bulbs should be replaced each 1436.9 hours.
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:

How often should the bulbs be replaced so that no more than 1% burn out between replacement periods?
This is the first percentile of hours. So it is X when Z has a pvalue of 0.01.
So it is X when Z = -2.33.




The bulbs should be replaced each 1436.9 hours.
The factors of 27 are 1, 3, 9, and 27 .
A prime number has only two factors. They are ' 1 ' and itself.
27 has four factors, so it's not prime.