Answer:
Cos (5π/3)
Cos (π/6)I think this one
Answer:
D) 171 cm²
Step-by-step explanation:
You don’t actually need to decompose it. You could just do it as a trapezoid:
(15+23)/2=19
19x9=171
If you want to decompose it into 2 triangles and a rectangle:
10=15x9=135
1/2(3)(9)=13.5
1/2(5)(9)=22.5
135+13.5+22.5=171 also
Answer:

Step-by-step explanation:
![\left[\begin{array}{ccc}x + 3y = 7\\x - 3y = 7\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%20%2B%203y%20%3D%207%5C%5Cx%20-%203y%20%3D%207%5Cend%7Barray%7D%5Cright%5D)
Isolate
for
:
Substitute
:

Isolate
for
:
For

Substitute 



The solution to the system of equations are:

Hope I helped. If so, may I get brainliest and a thanks?
Thank you. Have a good day! =)
Answer:
210.53
Step-by-step explanation:
here
hope it helps