The vertices of a right triangle are (-6, 4), (0.0) and (x, 0). find the value of x.

a. -4

b. -6

c. 6

d. 0

Hello here is a solution :
let A(-6;4)  O(0;0) B(x; 0)
i'have : OA² = OB²+AB² ( pytagore theorem)
 OA² = (-6-0)² +(4-0)² = 36 +16 =52
 OB² = (x-0)² + (0-0)² = x²
AB²  = (x+6)² +(0-4)² = x²+12x+36 +16 = x²+12x+52
52 = x² + x²+12x+52
2x² +12x=0
2x(x+6) =0
2x=0 or x+6 = 0
x=0  or x= -6
conclusion : x = -6
if x = 0 i' have not the triangle

He secknd step was the answer to them

No solution : there is no number of boxes that she bought