This is a power of a point problem.
So we have DA*DB = DY*DZ
or 3x*(3x+8) = x*(32+x)
9x^2 + 24x = 32x + x^2
8x^2 -8x = 0
(we can eliminate 0 as an option)
8x - 8 = 0
8x = 8
x = 1
DA = 3*1
DA = 3
