Answer:
(D) 
Step-by-step explanation:
Two variables x and y are proportionally related if they can be written in the form y=kx, where k is the constant of proportionality.
From the given options, if 
(B)
is of the form y=kx
(C)
is of the form y=kx with
as
in its lowest form.
(C)
is of the form y=kx with
as
in fractional form.
On the Contrary,
In Option D,
does not represent a proportional relationship between x and y. The constant of proportion is supposed to be a product of x.
Answer:
Shane started the problem correctly
Step-by-step explanation:
We are given problem (-5) - (-1 3/4).
Mariah started the problem as (-5) + 1 - 3/4
Shane started the problem as (-5) + 1 + 3/4
We need to find who started the problem correctly.
The problem should be started by converting the mixed fraction into improper fraction i,e

Now we will solve bracket by multiplying -1 with term inside the bracket i.e


Let's compare both the procedures now:
Mariah:



Therefore, Mariah did not start the problem correctly.
Shane:



Therefore, Shane started the problem correctly.
450/30
15
15/3x =5
x= 5
5+2y= 315
5-5+2y =315-5
2y = 310
2y/2 = 310/2
y=155
Step-by-step explanation:
450/45
10
2x+4y=450
2×5=10
10+(4×155)
=620/155
=4
10/5=2
Answer:
5/24 or 20.8%
Step-by-step explanation:
Probability that the 7th grader is a boy = number of boys/(total kids) = 4/(4+4) = 1/2
Probability that the 8th grader is a boy = 5/(5+7) = 5/12
Probability that both are boys = 1/2*(5/12) = 5/24 or 20.8%
Answer:
00:13 mm:ss
Step-by-step explanation:
There are 60 seconds in a minute. This fact can be used to convert the time period(s) to minutes and seconds either before or after you do the subtraction.
<h3>Difference</h3>
It is often convenient to do arithmetic with all of the numbers having the same units. Here, we are given two values in seconds and asked for their difference.
100 s - 87 s = (100 -87) s = 13 s
The difference between the two time periods is 0 minutes and 13 seconds.
<h3>Conversion</h3>
If you like, the numbers can be converted to minutes and seconds before the subtraction. Since there are 60 seconds in a minute, the number of minutes is found by dividing seconds by 60. The remainder is the number of seconds that will be added to the time in minutes:
87 seconds = ⌊87/60⌋ minutes + (87 mod 60) seconds
= 1 minute 27 seconds
100 seconds = ⌊100/60⌋ minutes + (100 mod 60) seconds
= 1 minute 40 seconds
Then the difference is found in the same way we would find a difference involving different variables. (A unit can be treated as though it were a variable.)
(1 min 40 s) -(1 min 27 s) = (1 -1 min) + (40-27 s) = 0 min 13 s
The difference between the two time periods is 0 minutes and 13 seconds.