Question 1131020


{{{7x+8y=-18}}}......eq.1
{{{7x+5y=-6}}}......eq.2
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{{{y=(-7x-18)/8}}}-> so far you did it correctly

{{{7x+5(-7x-18)/8=-6}}}

{{{7x+(-35x-90)/8=-6}}}.....both sides multiply by {{{8}}}

{{{56x-35x-90=-48}}}

{{{21x=-48+90}}}

{{{21x=42}}}

{{{x=42/21}}}

{{{x=2}}}

go back to {{{y=(-7x-18)/8}}}, substitute {{{2}}} for {{{x}}}

{{{y=(-7*2-18)/8}}}

{{{y=(-14-18)/8}}}

{{{y=-32/8}}}

{{{y=-4}}}


so, system does have solution and it is: {{{x=2}}} and {{{y=-4}}}