F(X) means the function of X. So we just plug in 12 for X.
(3/4(12))+5/6=36/4+5/6=9+5/6=59/6
You need to use the steps of a^2+b^2=c^2
A and B are the legs. C is the hypotenuse.
If we follow that through, we find the answer is 20.
-2x -1 means the answer is 2
Day = 8 4/5 ÷ 4
day = 44/5 ÷ 4
day = 44/5 × 1/4
day = 44/20
day = 11/5
day = 2 1/5