Question 966700
1.{{{a+c=0}}}
2.{{{a+2b=-7}}}
3.{{{c-1=3}}}
4.{{{4d-6=2d}}}
From eq. 3,
{{{c=4}}}
From eq. 4,
{{{2d=6}}}
{{{d=3}}}
Then substituting into eq. 1,
{{{a+4=0}}}
{{{a=-4}}}
And substituting into eq. 2,
{{{-4+2b=-7}}}
{{{2b=-3}}}
{{{b=-3/2}}}