Question 938284

{{{2a+b=3}}}...........eq.1
{{{-3a-2b=-1}}}.........eq.2
_____________________multiply eq.1 by {{{2}}} 

{{{4a+2b=6}}}...........eq.1
{{{-3a-2b=-1}}}.........eq.2
_____________________....... add eq.1 and eq.2

{{{4a+cross(2b)-3a-cross(2b)=6-1}}}

{{{highlight(a=5)}}}

go to eq.1 or eq.2, substitute {{{5}}} for {{{a}}} and solve for {{{b}}}

{{{2a+b=3}}}...........eq.1

{{{2*5+b=3}}}

{{{10+b=3}}}

{{{b=3-10}}}

{{{highlight(b=-7)}}}