The answer is three significant figures. The 1 and the 7 are both significant, because they are non-zero quantities.
This is where significant figures gets a little more complicated, because if a zero is used as a placeholder (i.e. 0.00027 cm) then it is insignificant.
But in the case above, the zero isn't being used as a placeholder, and thus, is significant.
Answer: 
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Reason:
Plot the points (0,0) and (r,s). You can place (r,s) anywhere you want.
Connect the two points mentioned and form a right triangle such that the segment from (0,0) to (r,s) is the hypotenuse of said right triangle.
The horizontal leg has a length of r-0 = r units, while the vertical leg will be 's' units.
Check out the diagram below.
We then apply the pythagorean theorem to say
where h is the hypotenuse. Solving for h gets us
. We only focus on the positive square root since a negative hypotenuse makes no sense.
Since we made the hypotenuse the segment with endpoints (r,s) and (0,0), this means the hypotenuse length and the distance are the same thing.
Therefore, the distance from (r,s) to (0,0) is 
As an alternative, you can use the distance formula to get the same answer. The distance formula is effectively the pythagorean theorem phrased a different way.
Answer:
x=8
Step-by-step explanation:
-5(x-3)=-25
Divide each side by -5
-5/-5(x-3)=-25/-5
x-3 = 5
Add 3 to each side
x-3+3 = 5+3
x = 8
Your answer is gonna be 1/25