Question

find the value of x for which the distance between the points a(x,2) and b(9,8) is 10

Answer 1

100 = (9-x)2+(-8-2)2

100=81+x2+18x +100

100-100=x2+18x+81

0=x2+9x+9x+81

0=x(x+9)+9(x+9)

x=-9