Answer:
C. y +3 = x +3
Step-by-step explanation:
We need to find in below option x has direct variation with y.
We solve for each;
A. 
From above equation we can state that 2 times y is equal to 7 less than 3 times of x.
Hence it doesn't represent direct variation.
B. 
Solving above expression we get;

From above equation we can state that y is equal to 10 more than x.
Hence it doesn't represent direct variation.
C. 
Solving above expression we get;

From above equation we can state that y is equal to x.
Hence it represent direct variation.
D. 
Solving above expression we get;

From above equation we can state that 4 times y is equal to 2 less than 4 times of x.
Hence it doesn't represent direct variation.
Hence the Answer which represent direct variation of x and y is,
C. 
Answer:
B. -4x+5y=40
Step-by-step explanation:
y * 5= (4/5 x + 8) * 5
5y = 4x + 40
-4x + 5y =40
Answer: 75 students.
Step-by-step explanation:
In the data set we have a total of 10 + 8 + 7 + 5 = 30 students.
of those, 10 want to go to the park, the percentage is:
(10/30)*100% = 33.3%
Then, out of the 225, we can expect that a 33.3% (or 0.333 in decimal form) want to go to the park, this is:
N = 225*0.333% = 74.925
We can roud it up, and get N = 75
So Sally can expect that 75 students want to go to the park
You have to start by using the distributive property. So you take the number next to the parentheses which is “8” and you multiply it with “2x”. This gives you “16x”. Then you multiply “8” with “3” and that gives you “24”. You now have the equation “16x + 24 = 48”.
The next step is to subtract “24” with “48”. This leaves you with “24”. Then you now have “16x = 24” as your new equation. The last step is to divide “16x” with “16”, this cancels it out with itself. Then you divide “24” with “16” and you get 1.5. So “X” equals 1.5 or you can convert it into a fraction witch gives you “3/4”.
Answer:
This is a reflection about the x-axis.
Step-by-step explanation:
A reflection about the x-axis has the rule
[x,y]-> [x,-y].
Therefore
M[x,y] = [x,-y}
Let M=
|a b|
|c d|
Then the matrix multiplication gives
ax+by=x.............(1)
cx+dy=-y............(2)
Solving the previous equations (1) and (2) gives
a=1, b=0
c=0, d=-1
giving M as
|1 0|
|0 -1|