1) A circle has centre (0,0). The point (15 , 8) is a point on the circle. Find the equation of the circle.
(15,8) is the distance from centre to circumference aka the radius.
Create a right angle triangle around the points and work out the radius,
a^2+b^2=c^2
15^2+8^2=289
sqrt(289)=17
x^2+y^2=17
sorry went brain blank a second
I think you made a typo....
x^2 + y^2 = 17^2