Question 639514


{{{4a + 9b = 8}}}......1
{{{8a + 6c = -1}}}.....2
{{{6b + 6c = -1}}}.....3
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{{{4a + 9b = 8}}}......1...solve for {{{a}}}

{{{4a = 8-9b}}}

{{{a = 8/4-9b/4}}}

{{{a = 2-2.25b}}}..........plug in 2
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{{{8(2-2.25b) + 6c = -1}}}.....2

{{{16-18b + 6c = -1}}}....solve for {{{b}}}

{{{-18b = -1-16-6c}}}

{{{-18b = -17-6c}}}...both sides multiply by {{{-1}}}

{{{18b = 17+6c}}}

{{{b = 17/18+6c/18}}}

{{{b = 0.94+0.33c}}}.............plug in 3
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{{{6(0.94+0.33c) + 6c = -1}}}.....3..solve for {{{c}}}

{{{5.64+1.98c + 6c = -1}}}

{{{1.98c + 6c = -1-5.64}}}

{{{7.98c = -6.64}}}

{{{c = -6.64/7.98}}}

{{{highlight(c = -0.83)}}}
____________________________now find {{{b}}}

{{{b = 0.94+0.33c}}}

{{{b = 0.94+0.33(-0.83)}}}

{{{b = 0.94-0.2739}}}

{{{highlight(b = 0.6661)}}}
______________________________now find {{{a}}}


{{{a = 2-2.25b}}}

{{{a = 2-2.25(0.6661)}}}

{{{a = 2-1.498725}}}

{{{highlight(a = 0.5)}}}
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check:

{{{4a = 8-9b}}}

{{{4*0.5 = 8-9*0.6661}}}

{{{2 = 8-5.9949}}}...round to nearest whole number

{{{2 = 8-6}}}

{{{2 = 2}}}