added degrees or "x=" to answer form on 16 exercises, also cleaned up hints on 1: fix #24889; fix #15290; fix #24748; fix #24565; fix #24630; fix #25290; fix #25586;

#14748, #13832, #13822, #14747, #13044 look like they can also be closed... these look like problems before answer type degrees was removed.

fix #24889; fix #15290; fix #24748; fix #24565; fix #24630; fix #25290; fix #25586