Question 1205740

{{{36x+54y=450}}} ......eq.1
{{{12x+15y=135}}}.....eq.2....both sides multiply by{{{ 3}}}
---------------------

{{{36x+54y=450}}} ......eq.1
{{{36x+45y=405}}}.....eq.2
---------------------------subtract eq.2 from eq.1

{{{36x+54y-(36x+45y)=450-405}}}
{{{36x+54y-36x-45y=45}}}
{{{9y=45}}}
{{{y=45/9}}}
{{{y=5}}}

go to eq.1, substitute{{{ y}}}

{{{36x+54*5=450}}}
{{{36x+270=450}}}
{{{36x=450-270}}}
{{{36x=180}}}
{{{x=180/36}}}
{{{x=5}}}

solution:

ordered pair ({{{5}}},{{{5}}})