supplementary angles add up to 180°.
x = measure of such angle
x + 20 = measure of her sibling.
since "x" has 20 less than her sibling, then clearly her sibling has to have 20 more than "x".

Answer:
i think C. y = -(4/3)x -4 is answer
THE CORRECT ANSWER IS N=4
Use a porportion to help better and speed up the process