Fine two vectors in opposite directions that are orthogonal to the vectoru.

u= <((1/2)i,(-2/3)j

Solution:Two vectors are orthogonal if they are perpendicular.

There fore a vector v =(x,y) is orthogonal to u if

(x,y) . (1/2,-2/3) =1/2x-2/3y=0

now I have to find values of x and y that makes 0..?

I am stuck here...plz help? not getting right ans....