Question

The distance between A (1, 3) and B (x, 7) is 5. The value of x (> 0) is :

• A. 4
• B. 2
• C. 1
• D. 3

Answer 1

The correct option is A

4

$A{B}^2$ = ${(x-1)}^2$ + ${(7-3)}^2$

$5^2$ = ${(x-1)}^2+16$

$9={(x-1)}^2$

$x-1=3$ , $x-1=-3$

$x=4,-2$