Geometry Practice Test 5

A (x, o) B = (- 7, 0)
Distance between the two points are:
D = $\sqrt{{\left({\mathit{x}}_2-{\mathit{x}}_1\right)}^2+{\left({\mathit{y}}_2-{\mathit{y}}_1\right)}^2}$
${\mathit{x}}_1$ = x
${\mathit{y}}_1$ = 0
${\mathit{x}}_2$ = - 7
${\mathit{y}}_2$ = 0
$\sqrt{{\left(-7-\mathit{x}\right)}^2+{\left(0-0\right)}^2}$ = 10
$\sqrt{\left(49+{\mathit{x}}^2+14\mathit{x}\right)}$ = 10
${\mathit{x}}^2$ +14x + 49 = 100
${\mathit{x}}^2$ +14x − 51 = 0
${\mathit{x}}^2$ +17x − 3x − 51 = 0
x(x +17)− 3(x +17) = 0
(x − 3)(x +17) = 0
x = 3,−17