Question 826796
{{{y = 2x}}}....eq.1
{{{x + y = 6}}}....eq.2
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{{{x + y = 6}}}....eq.2...substitute {{{y}}} from eq.1

{{{x + 2x = 6}}}....solve for {{{x}}}

{{{3x = 6}}}

{{{x = 6/3}}}

{{{highlight(x = 2)}}}

go to {{{y = 2x}}}....eq.1 plug in {{{x=2}}} and find {{{y}}}

{{{y = 2*2}}}

{{{highlight(y = 4)}}}