Question 390073
{{{a+5=-5a+5}}}.........add {{{5a}}} to both sides

{{{a+5 + 5a =-5a + 5a +5}}}

{{{a+5 + 5a =cross(-5a + 5a) +5}}}

{{{a+5 + 5a = 5}}}..........add {{{-5}}} to both sides

{{{5 + 6a -5 = 5 -5}}}

{{{cross(5) + 6a - cross(5) = 5 -5}}}

{{{6a  = 0}}}

{{{a  = 0}}}