Answer: Largest exterior angle is 85.44 degrees
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Explanation
Rule: The exterior angles of any polygon always add to 360 degrees
Based on that rule, we simply add up the 8 expressions given to us and set that sum equal to 360. Then we solve for x
(x+12)+(2x-3)+(3x+10)+(3x+15)+(2x-19)+(4x-1)+(4x-10)+(6x) = 360
(x+2x+3x+3x+2x+4x+4x+6x)+(12-3+10+15-19-1-10) = 360
25x+4 = 360
25x = 360-4
25x = 356
x = 356/25
x = 14.24
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Once you determine the value of x, you plug that into each of the 8 exterior angle expressions
In short we have these 8 exterior angles
We see that 85.44 degrees is the largest exterior angle (which is the angle that corresponds to the 6x). This makes sense because the 6 is the largest x coefficient compared to something like 2x-3 or 3x+10 which have x coefficients of 2 and 3 respectively.