Answer:
C. 113°
Step-by-step explanation:
(7x - 1) + 79° = 21x + 8
• An exterior angle of a triangle is equal to the sum of its two interior opposite angles.
[tex](7x - 1) +79 = 21x + 8 \\ 7x - 1 + 79 = 21x + 8 \\ 7x + 78 = 21x + 8 \\ 78 - 8 = 21x - 7x \\ 70 = 14x \\ \frac{70}{14} = x \\ 5 = x \\[/tex]
NRS = 21x + 8
[tex]21x + 8 \\ 21(5) + 8 \\ 105 + 8 \\ {113}^{o} [/tex]
