We know that the sum of the internal angles in each triangle is 180°.
Therefore we have the equation:
[tex] m\angle C+m\angle D+m\angle E=180^o [/tex]
substitute and solve:
[tex] 79+(6x+11)+(7x-14)=180\\(6x+7x)+(79+11-14)=180\\13x+76=180\ \ \ |-76\\13x=104\ \ \ |:13\\x=8 [/tex]
We have
[tex]m\angle N=3x+18[/tex]
substitute the value of x to the expression:
[tex]m\angle N=3(8)+18=24+18=42[/tex]
Answer: m∠N = 42 degrees
