I have the two equations:

1) x + y = qsin(theta)

2) z = rcos(theta)

The question is eliminate theta and solve for q in terms of x, y, z, and r.

I'm not sure what eliminating theta means, but I have:

arcsin((x+y)/q) = theta

and I substituted that into my top equation. I have no clue on what I should do now.

Also,I don't understand how I can solve for q in terms of z and r when q isn't in the equation with z and r.