Let p(x)=sqrt(-x), and q(x)=8x^2+10x-3. The domain of p(q(x)) can be written in the form a <= x <= b. Find b-a.

"Let p(x)=sqrt(-x), and q(x)=8x^2+10x-3. The domain of p(q(x)) can be written in the form a <= x <= b. Find b-a."