Answer:
x = 27
Step-by-step explanation:
We can say that sum of all interior angles adds up to: 180°, therefore;
(3x - 17) + (2x - 5) + (x + 40) = 180°
=> now add like terms together:
=> 3x + 2x + x = 6x
=> -17 + (-5) + 40 = 18
Therefore;
6x + 18 = 180°
6x = 180 - 18
6x = 162
x = 162/6
x = 27
Hope this helps!
