You can put this solution on YOUR website! M = 1.05W (man is 5% older than wife)
let's work with some actual numbers so it's easier to see.
If Wife is 50, then Man is 52.5
(=1.05 (Man is 105% of Wife's age)
To find Wife's age, reverse: =95.24 (Woman is 95.24% of Man's age, or 4.76% younger)