ok but what's the question? u gave us info but what's the question
The way I figured this one out was saying that if it takes 2lbs to stretch it to 12 inches and 5lbs to stretch to 18 inches that means that 3 additional pounds = 6 inches. Therefore, each additional pound is 2 inches. We know already that with 2 lbs it was 12 inches in length and we can also say that 2 lbs = 4 inches. So subtract 4 from 12 and you end up with the answer of 8 inches.
Let
C----------> the center of a circle
C (-4,5)
A-----------> a point on the circle
A (-9,10)
we know that
the distance between point A and point C is the radius of the circle
A (-9,10) C (-4,5)
d=√[(y2-y1)²+(x2-x1)²]--------> √[(5-10)²+(-4+9)²]
=√[(-5)²+(5)²]------> √[(25)+(25)]---------> √50
d=7.07 units
r=d--------> r=7.07 units
the equation of a circle is
(x+4)²+(y-5)²=50
see the attached figure
the answer is
the radius of a circle is 7.07 units