Answer: 139°
Reasoning:
Angle 3 and 5 are congruent, so you can put their expressions equal to each other and solve.
14x-1=9x+14
To isolate the x to one side, subtract the 9x from the 14x.
5x-1=14
Now to get the constants on one side, add the 1 to the 14.
5x=15
Now divide both sides by 5 to isolate the x.
5x/5=15/5
x=3
Now that we know that, we can figure out angle 3.
9(3)+14
27+14= 41
Angle 3 = 41°
Now that we know what angle 3 is, we can subtract it from 180° to figure out angle 8 since angle 3 and 8 are supplemtary angles, aka linear pairs.
180°- 41°= 139°
Double checking your answer:
41°+139°=180°
