Complimentary angles add up to 90 degrees
2x + 4x = 90
6x = 90
x = 90/6
x = 15 <==
42/51 = 14/17
14/17 x 100 = 82.35294
=82.4%
280=100%
210=x% ( cross multiply)
280X=21000
X=75%
52/72
13/18 is your answer. Therefore, C.
If I remember correctly this would be obtained from the factors of -24
so i think its +/-1, +/-2, +/- 3, +/- 4, +/- 8, +/- 6 , +/-12, +/-24
Sorry but i cant be sure