find a number that is 15 more than 4 times it's oppisite

Answer 1

"opposite" has no mathematical meaning. Do you mean negative, reciprocal, or what?

negative:
n = 15 + 4(-n)
n = 15 - 4n
5n = 15
n = 3

3 is 15 more than -12

reciprocal:

n = 15 + 4/n
n^2 - 15n - 4 = 0
n = (15 +/- sqrt(209)]/2

judging from the sophistication of the question, this is not what was intended.