Find all points on the x-axis that are 10 units from the point (7, 6). (Hint: First write the distance formula with (7, 6) as one of the points and (x, 0) as the other point.)

Answer 1

a circle with radius 10 and center at (7,6)

(x-7)^2 + (y-6)^2 = 10^2 = 100
where does it hit the y axis (y=0) ?

(x-7)^2 + 36 = 100

(x-7)^2 = 64

(x-7) = +/- 8
x = 7 +/- 8

if x = 7+8 then x = 15
if x = 7-8 then x = -1