writing and linear equations
posted by mari .
the measure of one angle is described as twelve more than four times a number. its supplement is twice as large. find the measure of each angle.

if the angle is x, its supplement is 180x, so just solve
180x = 2x
x=60
What's all this nonsense about x=4n+12?
If you need to find "the number" then just solve that for n, given that x=60.