What is the volume of the sphere below?

The sum of two numbers is 86, and their difference is 20. find the two numbers

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.

Solve x+3y=6 and 4x-6y=6 by elimination . show work !