Question 1203967


{{{y = 2x - 3}}}....eq.1
{{{-6x + 3y = -9}}}.....eq.2
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using substitution

{{{-6x + 3y = -9}}}.....eq.2, substitute {{{y}}} from eq.1

{{{-6x + 3(2x - 3) = -9}}}

{{{-6x + 6x - 9 = -9}}}

{{{-6x + 6x = -9+9}}}

{{{0 = 0}}}


it means we have two lines on top of each other, or same line

let's check eq.2, solve for  {{{y}}} 

{{{-6x + 3y = -9}}}.....eq.2

{{{ 3y = 6x -9}}}.....both sides divide by {{{ 3}}}

{{{ y = 2x -3}}}   which is same as eq.1