Question 126002


{{{3a - 2b =21}}}..............(1)

{{{a + 3b = -4}}}..............(2)

take (2) and solve for {{{a}}}

{{{a + 3b = -4}}}..............(2)

{{{a = -3b -4}}}..........(I)..........substitute in (1)

{{{3(-3b -4) - 2b =21}}}

{{{-9b -12 - 2b =21}}}

{{{-11b =21+12}}}

{{{-11b = 33}}}

{{{b = 33/-11}}}

{{{highlight(b = -3)}}}


{{{a = -3b -4}}}..........(I)

{{{a = -3(-3) -4}}}

{{{a = 9 -4}}}

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


check:

{{{3*5 - 2(-3) =21}}}..............(1)

{{{15 + 6 =21}}}

{{{21 =21}}}