Answer:
C: 12.5
Step-by-step explanation:
The sides x and 11 could be defined as the Adjacent angle and the Hypotenuse. This means that we will use the cos function to solve this.
First we can set up our equation

Next we can solve for x by multiplying by x and dividing by 

Answer:70 degrees and 150 degrees
Step-by-step explanation: The angles of a quadrilateral add up to 360. So the sum of the two angles is 360 - (55+ 85) = 220.
After that you can model the sum of the angles with an equation:
7x + 15x = 220
22x = 220
x = 10
then you plug in x for each angle 7(10) = 70 and 15(10) = 150
Judging by the question I noticed that I can simplify the equation 3x-x+2=12 by one step.
The outcome of simplification should be 2x+2=12.
Next you must subtract 2 from both sides to isolate the x. The new equation should be 2x = 10.
Lastly you must divide both sides by 2, the answer you should get is x=5, D.