-x+3y=6 x+3y=18 elimination using addition and subtraction

The number of pages in the u.s. tax code exceeds the number of pages in the king james bible by 18,528. the combined number of pages in the tax code and the bible is 21,472

Write the sine and cosine values of a, b, respectively, in the figure for (1) and (2) + explanation.

I’ve been trying all day to figure this puzzle out. i need the work for it aswell. it is a factoring polynomials tarsia. the image is below.