What is the value of the expression -c+(-d) when c=-3.5 and d= -12.8

Alex drew a circle with right triangle prq inscribed in it, as shown below: the figure shows a circle with points p, q, and r on it forming an inscribed triangle. side pq is a chord through the center and angle r is a right angle. arc qr measures 80 degrees.

Using graph paper, determine the line described by the given point and slope. click to show the correct graph below.(0, 0) and 2/3

Cd is the perpendicular bisector of both xy and st, and cy=20. find xy.