Answer
B) mJAB = 115°
D) mCBA = 55°
Explanation
You know that C A J are points that are collinear, therefore,
180 - (11x - 6) = angle CAB
Which is:
186 - 11x
Use the fact that angles in a triangle add up to 180.
180 = 60 + 4x + 11 + 186 - 11x
180 = 257 - 7x
180 - 257 = - 7x
-77 = -7x
x = 11
Now you know that x = 11 and angle CAB is 186 - 11x simply substitute
186 - (11 x 11) = 65°
So angle CAB is 65° (No option in your multiple choice answers fits this)
Now try to find the value for angle CBA, substitute x = 11 into 4x + 11
4x11 + 11 = 55° (that’s option D where mCBA = 55°
Now try to find the value of angle JAB, you know x = 11 and it’s value is 11x - 6
11 x 11 - 6 = 115° (this is option b)
