Question

47. If the distance between the points (2,-2) and (-1, x) is 5, one of the values ofx is
(a) -2
(b) 2
(c)-1​

Answer 1

option (b).. is the correct answer

Step-by-step explanation:

Let,

point A = (2,-2)

point B = (-1,X)

Distance AB = 5 units

Applying distance formula,

AB² = (x2 - x1)² + (y2 - y1)^²

(5)² = (-1 - 2)² + (X + 2)²

25 = 9 + X²+ 4 + 4X 

X² + 4X - 12 = 0

X² + 6X - 2X - 12 = 0

X(X + 6) -2(X + 6) = 0

(X - 2) (X + 6) = 0

Therefore, 

X = 2   or X = -6

Answer 2

(-1-2)^2 + (x-(-2))^2= 5^2
3^2 + (x+2)^2 = 25
(x+2)^2 = 25-9=16
(x+2) =4
x = 2