Answer:
(x -1)² +(y -4)² = 25
Step-by-step explanation:
The equation of a circle in standard form is ...
(x -h)² +(y -k)² = r² . . . . . . . circle with center (h, k) and radius r
The graph shows your circle has its center at (1, 4) and its radius is 5. Then the equation is ...
(x -1)² +(y -4)² = 25
Answer: Choice D) 
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Work Shown:

Explanation:
First I subtracted y/b from both sides. Then I multiplied both sides by 'a' to fully isolate x. You can optionally distribute the 'a' through to each term inside the parenthesis, but your teacher has chosen not to do this.
X=cost of one box of popcorn.
we can suggest this equation:
3x+1.75=9.25
3x=9.25-1.75
3x=7.5
x=7.5/3
x=2.5
Answer: the equation to find the cost of one box of popcorn is 3x+1.75=9.25, and the cost of one box of popcorn is $2.5.
In order to change from 35 to 62, we have to add 27. So, the question becomes: which percentage of 35 is 27?
To answer this question, we set this simple equation

And solving for x we have

So, if you change from 35 to 62, you have an increase of about 77%