The answer is C 1.312, -1.33, -1 3/9, -1 3/10
You get a common denomiator so which is 18. So mulitply 8/9 by 2 which is 16/18 and multiply 5/6 by 3 which is 15/18 and add 16/18 and 15/18 together and you get.....35/18 and you divide. 35 divided by 18 is 1 13/18
a. 12 deg, b. 168 deg
We can create a systems of equations using this information, since supplement angles add up to 180 deg and complementary angles add up to 90 deg, when angle = x deg and supplement = y deg,
x + y = 180
y = 2(90 - x ) + 12
Solving:
x + 2(90 - x) + 12 = 180
-x + 180 + 12 = 180
x = 12
12 + y = 180
y = 168