Question

Find a point on the y-axis that is equidistant from the points (7, −7) and (1, 1).

Answer 1

Hello : 
a point on the y-axis is : P( 0, y)
PA = PB  or  PA² = PB².... A(7, -7)    B(1,1)
(7-0)²+(-7-y)² = (1-0)² + (1-y)²
49+49+14y+y² = 1+1-2y+y²
16y = - 96
y= - 6