1. Points A and B are in the first quadrant, and O = (0,0) is the origin. (A point is in the first quadrant if both coordinates are positive.) If the slope of \overline{OA} is 1 and the slope of \overline{OB} is 7, and OA = OB, then compute the slope of \overline{AB}.

2. The line y = (3x + 7)/4 intersects the circle x^2 + y^2 = 25 at A and B. Find the length of chord \overline{AB}.

3. The lines y = \frac{5}{12} x and y = \frac{4}{3} x are drawn in the coordinate plane. Find the slope of the line that bisects these lines.