Answer:
cos X = 
Step-by-step explanation:
simplify 15/39
- 5/12 + ( - 1/4) =
Adding two negatives results in a negative
-1/4 = -3/12
-3/12 + -5/12 = -8/12
-8/12 + 3/12 < Subtract and take the sign of the BIGGER number.
8 - 3 = 5
- 5/12
Answer: - 5/12
The answer is b. Notice that the problem is looking for the reaction to product ratio, which is tricky because it's easy to follow the order of the column and calculate the inverse of it. Check the first ratio, 0.3/2=0.15, we can immediately choose b out of the other 4 choices.
It cannot be 30, because the sum of two sides should be more than third side
-not D
10+18=28 <30
it cannot be 6 +10 < 18
it cannot 8
8+10=18
so it is has to be C) 12
12+18>10
10+12>18
10+18>12
answer C. 12 cm