Question 482901
Assume this is The problem:
 {{{(7-2n)/(7+2n)}}} = {{{1/18}}}
Cross multiply and you have
 7 + 2n = 18(7-2n)
 7 + 2n = 126 - 36n
2n + 36n = 126 - 7
38n = 119
n = {{{119/38}}}