Is it possible for the cosine ratio to be the reciprocal of the secant ratio? or is the secant ratio only the reciprocal of the cosine?

Match the equivalent expressions. x - 3y + 12 12 - 3y - 2x + x + 2x 3x + 2y - 2x + y + 12 3y + 12 3x + y - 12 4y + 3y + 3x - 6y - 10 - 2 x + 3y + 2x - 3x + 7 + 5 x + 3y + 12 5 + 2y + 7x - 4x + 3y - 17

Ill mark the brainliest if you me with the these three questions 7,8,9

Another type of subtraction equation is 16-b=7. explain how you would sole this equation then solve it.