Question 52246
We know nothing about the third number, so let's call it y.  So, we have {{{75=x+(x+8)+y}}} which simplifies to {{{75=2x+8+y}}}.  Further simplification results in {{{67=2x+y}}}.  Continue solving for x and we get {{{67-y=2x}}} and finally{{{(67-y)/2=x}}}.