Question 88282
by re-arranging you mean?


{{{ c = b / (a + b) }}}
{{{ c(a + b) = b }}} by taking the denominator to the other side to remove the fraction part.
{{{ ac + bc = b }}} multiplying out the bracket
{{{ ac = b - bc }}} collecting all terms with "b" in on one side and all others on the other side
{{{ ac = b(1 - c) }}} factorise to get the "b" by itself
{{{ ac/(1 - c) = b }}} removing the unwanted factor by dividing.


jon