Answer:

Step-by-step explanation:
Equation: 
Step 1: Balance both parts of the equation.




Step 2: Reduce 14 from both parts of the equation.


Step 3: Split both sides by 10, because
.


Therefore, x = -1.
I’d say the second one, the fourth one and the fifth one.
Hope it works :)
Answer: Choice B
(-2, 5)
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Explanation:
The original system is

Multiply both sides of the second equation by 3. Doing so leads to this updated system of equations

Now add straight down
The x terms add to -4x+3x = -1x = -x
The y terms add to 3y+(-3y) = 0y = 0
The terms on the right hand sides add to 23+(-21) = 2
We end up with the equation -x = 2 which solves to x = -2
Now use this to find y. You can pick any equation with x,y in it
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-4x+3y = 23
-4(-2)+3y = 23
8+3y = 23
3y = 23-8
3y = 15
y = 15/3
y = 5
Or
x-y = -7
-2-y = -7
-y = -7+2
y = -5
y = 5
Either way, we get the same y value.
So that's why the solution is (x,y) = (-2, 5)
If you rotate about the circumcentre of a regular polygon 72° it will overlap with the original image.
60x=y
To find this answer, find what y/x=m would be for m
150/2.5=60
240/4= 60
330/5.5=60
420/7=60