Question 938968
 substitute {{{x = (-1/4)y + 5}}}  in 3x + 2y = 0
   {{{  3((-1/4)y + 5) +2y  =0}}}
   {{{ (-3/4)y +15 +2y= 0}}}
      {{{  y((-3/4) +2) +15 = 0}}}
          {{{ y (2-3/4) =-15}}}
         {{{  y ( 2*(4/4) -3/4)= -15}}}
                {{{y(8/4 -3/4)= -15}}}
           {{{ y((8-3)/4) = -15}}}
             {{{ y(5/4)  = -15}}}
            {{{ y  = -15*(4/5)}}} 

                y= -12