Answer:
This equation system has no answer
Step-by-step explanation:

Answer:
The swimmer must complete the 200-meter backstroke in no more than 130 seconds.
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:

Fastest 6%
At most in the 6th percentile, that is, at most a value of X when Z has a pvalue of 0.07. So we have to find X when Z = -1.555.




The swimmer must complete the 200-meter backstroke in no more than 130 seconds.
Answer:
The number of unsold cakes was 2
Step-by-step explanation:
<u><em>The question in English is</em></u>
In the school Francisco I. Madero of Ciudad Delicias, the celebration was held for commemorate the arrival of spring, after the parade the stalls were set up of the kermesse. The first grade group bought 8 cakes and sold 3/4 of the total.
How much of the cake was not sold?
Let
x ----> number of cakes sold
y ----> number of cakes that didn't sell
we know that
The first grade group bought 8 cakes
so
-----> equation A
The first grade group sold 3/4 of the total.
so
---> equation B
substitute equation A in equation B

Find the value of y


therefore
The number of unsold cakes was 2
Answer: In the last steps, instead of multiply each side by 3, he has to divide each side by 3.
Step-by-step explanation:
Hi, Tobin makes the mistake in the last steps.
3(x-1.25) = 11.25
3x-3.75= 11.25
3x-3.75+3.75= 11.25+3.75
3x = 15
Until this step is the work ok.
Now, instead of multiply each side by 3, he has to divide each side by 3:
So:
3x /3 = 15/3
x = 5
Feel free to ask for more if needed or if you did not understand something.