Question 119801
Since we have the solution (x,-4), this means {{{y=-4}}}.


{{{4x-5y=8}}} Start with the given equation



{{{4x-5(-4)=8}}} Plug in {{{y=-4}}}



{{{4x+20=8}}} Multiply





{{{4x=8-20}}}Subtract 20 from both sides



{{{4x=-12}}} Combine like terms on the right side



{{{x=(-12)/(4)}}} Divide both sides by 4 to isolate x




{{{x=-3}}} Divide


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Answer:

So our answer is {{{x=-3}}}