PLS HELP I MEAN SOS ITS MAJOR! btw there r two questions

Both the red and blue line segments stretch from the center of the circle to a point on the circle. the length of the blue segment is 5. how long is the red line segment?

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

Atorch and a battery cost 2.50 altogether.the torch costs 1.50 more than the battery.what fraction of the total price is the torch? give your answer in its simplest form.