Answer:
x = 12
Step-by-step explanation:
Given: the overall angle m∠ADC = (16x − 55) and m∠ADB = 5x - 13.
To solve for x , you can make another equation where
90° (right angle) + m∠ADB = m∠ADC; substitute with terms given
90 + (5x - 13) = (16x - 55); remove parenthesis and combine numbers
5x + 77 = 16x - 55; subtract 5x from both sides
77 = 11x - 55; add 55 to both sides
11x = 132; divide by 11
x = 12
