Final answer:
After setting up and solving the equation based on the relationship between an interior angle and its corresponding exterior angle in a triangle, we find that the value of m is 23.
Step-by-step explanation:
To determine the value of m in the given triangle problem, we use the fact that the sum of the interior angle and its corresponding external angle of a triangle is equal to 180°. Given that m∠z = (5m - 16)° and the exterior angle to ∠z measures (3m + 12)°, we can set up an equation:
(5m - 16)° + (3m + 12)° = 180°.
Combining like terms, we get 8m - 4 = 180. Adding 4 to both sides gives us 8m = 184. Dividing both sides by 8 yields m = 23.
Thus, the value of m that satisfies the given conditions is 23.