Answer:
The value of n is 21.
Step-by-step explanation:
We are given that three of the exterior angle of the n-sided polygon are 50° each two of its interior angle are 127° and 135° and the remaining interior angle are 173 each.
As we know that the sum of all exterior angles of the polygon is 360°. Also, the number of remaining interior angles will be (n - 5).
And, the exterior angle = 180° - the interior angle.
So, according to the question;

150 + 53 + 45 + 7(n - 5) = 360
248 + 7n - 35 = 360
213 + 7n = 360
7n = 360 - 213
7n = 147
n = 
n = 21
Hence, the value of n is 21 and this is a 21-sided polygon.
13: multiply the amount by the tax rate (to make a percent a decimal move the decimal point 2 places to the left) and add the original amount and the taxed amount together. For 12 do above but then multiply the total by the tip rate and add together (basically the same as the tax again) :) I hope this helps
I believe the answer is X=15