Answer:
Download Photo math for help, it works really well and it shows the work.
Answer:

divide through out by -8 :

Answer is b
You know that the angle measurements in a triangle add up to 180 degrees.
using the equation 3x+4x+2x= 180, you can find x
Simplify:
9x=180
x=20
Your answer is B) x = 20
Hope this helps!
<h3>
Answer: 0.557</h3>
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Work Shown:

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Side note:
A similar formula is 
We can isolate the last term to get the first equation shown above.
What is the equation or number?..