Question

If the distance between the points (2,-2) and (-1,X) is 5 , one of the value of X is

Answer 1

Answer:

$using \: distance \: formula \\ = \sqrt{(x2 - x1) {}^{2} + (y2 - y1) { }^{2} } \\ 5 = \sqrt{( - 1 - 2) {}^{2} + (x + 2) {}^{2} } \\ 5 = \sqrt{1 + x {}^{2} + 4 + 4x } \\ 25 = x {}^{2} + 4x + 5 \\ x {}^{2} + 4x - 20 = 0 \\ now \: use \: quadratic \: formula \: to \: find \: value \: of \: x$