Question 351551
Plug the point into each equation,
{{{2x + ay + 2b = 0}}}
{{{2(-1) + a(3) + 2b = 0}}}
1.{{{3a+2b=2}}}
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.
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{{{ax - y - b = 1}}}
{{{a(-1)-3-b=1}}}
{{{-a-b=1}}}
2.{{{a+b=-1}}}
Multiply eq. 2 by (-1) and add to eq. 1,
{{{3a+2b-a-b=2+1}}}
{{{highlight(2a+b=3)}}}