the 3 angles need to equal 180 degrees.
Add them together:
42 + 5x + 7x +6 = 180
Combine like terms:
12X + 48 = 180
Subtract 48 from each side:
12X = 132
Divide both sides by 12:
X = 132 / 12
X = 11
Now replace x with 11 and solve CBE:
CBE = 7X + 6
7(11) + 6
77 + 6
CBE = 83 degrees
