8) in the figure at right, m_ abd is three
times m dbc. what is the measure of
z abd?

x = -3 or x = -6

Step-by-step explanation:

Solve for x over the real numbers:

3 x^2 + 27 x + 54 = 0

The left hand side factors into a product with three terms:

3 (x + 3) (x + 6) = 0

Divide both sides by 3:

(x + 3) (x + 6) = 0

Split into two equations:

x + 3 = 0 or x + 6 = 0

Subtract 3 from both sides:

x = -3 or x + 6 = 0

Subtract 6 from both sides:

 x = -3 or x = -6