Find the value of c

Answer:
D 23
Step-by-step explanation:
It all has to equal 180 because of supplementary angles and we know right angles are 90 degrees so you have 90 degrees to work with
(3 x 23 - 9) + (23 + 7) if you plug in 23 you get
69 - 9 = 60 + (23 + 7) then you do the other parenthesis
60 + 30 = 90
which is exact amount you need to make it 180 degrees because 90 + 90 = 180
Hope this helps,
Please make brainliest :)