hey i'm doing some revision for a test i have tommorw and this was one of the questions that came up, i'm fine with solving other trigonometric equations but im not too sure where to go with this one eg should i replace the (x-20 degrees) for say just y and come back and then find out x, but i thought i'd ask you intelligent people just to be sure

NOTE: I HAVEN'T WORKED IN RADIANS BEFORE SO COULD WE KEEP IT IN DEGREES please =)