urgent math help

Question

Use the given information to find the measure     . Hint: Use Angle Addition Postulate

 

Given: 

      

        

        

 

Find 

Answer 1

Angles are named by listing a point on a ray of the angle, the vertex and a point on the other ray. Thus the angle AOC has a point in the middle called B. Angle AOB is adjacent to Angle BOC. By the angle addition postulate add the two expressions together to have the total. Substitution in: 3x + 1 + 7x+ 4 = 105. Combining terms 10x + 5 = 105.

Subtract 5 from both sides: 10x = 100

Divide by 10: x = 10.

Substitute x back in for measurement of angle AOB: 3 ( 10) + 1 = 30 + 1 or 31