Answer:
X is 12.58 which rounds to 12.6
Step-by-step explanation:
Kono Dio Da!!
Hey!
First, let's write the problem,

Factor out the common term, which is 4,

Then, let's factor this part:

We are going to factor it using the difference of squares rule.

Our final factored answer would be,

Thanks!
-TetraFish
Answer:
12.9
Step-by-step explanation:
cos 72 = 4/x
x = 4/cos72
x = 12.9