given sin (a) = 5/13, pi/2 < a < pi and tan (b) = sqrt 13, pi/2 < B < pi what is tan (a-b)?

In the given figure ar(adf) =ar(cda) and ar(cdf) = ar(cdf). show that abdc and cdfe are trapeziums.

Last week , donnell practiced the piano 3 hours longer than marcus . together, marcus and donnell practiced the piano 11 hours . for how many hours did each young man practiced the piano

Which expression is equivalent to 64 - 9x^2?