Question 1152807
{{{R = x(A + B) }}} solve for {{{B}}}:

{{{R = xA + xB }}}

{{{R -xA =xB }}}

{{{R/x -xA/x =B }}}

{{{B=R/x -A  }}}

or, this way

{{{R = x(A + B) }}} 

{{{R/x = A + B }}} 

{{{R/x -A = B }}}