line bd bisects ∠abc. m∠abc = 7x. m∠abd = 3x + 36. find m∠dbc.
a. 108
b. 72
c. 180
d. 252

When we bisect an angle, the angle is cut in half. This means that ∠ABD = ∠DBC = 1/2 ∠ABC
Now that that's settled, we can set up the equation:
3x + 36 = 1/2(7x)
Multiply both sides by 2:
2(3x + 36) = 7x
Distribute:
6x + 72 = 7x
Isolate the variable by subtracting 6x:
72 = x

Now that you know x, you can solve for ∠ABD. And because that's equal to ∠DBC, you'll be getting that answer, too.
Therefore, the answer is B. 72

Hope this helped! Let me know if you have any questions and mark me Brianliest please:)