Question 314621
1.{{{4x+y=18}}}
2.{{{y=2x}}}
Substitute eq. 2 directly into eq. 1,
{{{4x+2x=18}}}
{{{6x=18}}}
{{{x=3}}}
Now use eq. 2 for y,
{{{y=2x=2(3)=6}}}
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{{{drawing(300,300,-2,8,-2,8,grid(1),circle(3,6,0.3),graph(300,300,-2,8,-2,8, 2x,18-4x))}}}