The expression is not simplified, because both the numerator and the denominator can be divided evenly
Answer:
D.
d = 3t; 90 mi
Step-by-step explanation:
Bicycling A bicyclist traveled at a constant speed during a timed practice period. Write a proportion to find the distance the cyclist traveled in 30 min.
elapsed time distance
10 min 3 mi
25 min 7.5 mi
Graph it. :)
Start at (0,0), then at 10 min. on the x-axis, go 3 spaces up on the y-axis and plot a point. Do the same for 25 min. and 7.5 miles. Draw a line through all of those points, and see where the line hits on the y-axis when the x-axis is at 30 min. :)
If two things vary directly it means their ratio is a constant. Therefore from the formula rt=d. r=d/t, r=3/10 or 7.5/25 which reduces to 3/10. This is the constant speed,the lable is mi/min. Now use (d/30)=(3/10) and solve for d. Cross multiply and 10d=90, or d=9 mi
Answer:
Due to the higher z-score, Jane did better in class.
Step-by-step explanation:
Z-score:
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 question:
Whoever's grade had the better z-score did better in class.
Mary's:
Mean of 85, standard deviation of 5, grade of 88. This means that 
. So
Jane's
Mean of 80, standard deviation of 10, grade of 88. This means that 
. So
Due to the higher z-score, Jane did better in class.
It is important because if you are adding and subtracfing and the decimals are off when your done with the equation you might end up with two decimals or numbers in the wrong place
Answer:
12 bikes
9 tricycles
Step-by-step explanation:
x+y=21
2x+3y=51
x=-y+21
2(-y+21)+3y=51
-2y+42+3y=51
y+42=51
y=9
x=12
