Question 181829
{{{x+y=8 }}} Start with the second equation



{{{x+highlight(3x-4)=8 }}} Plug in {{{highlight(y)=3x-4}}}. In other words, replace every "y" with 3x-4



{{{4x-4=8}}} Combine like terms



{{{4x=12}}} Add 4 to both sides



{{{x=3}}} Divide both sides by 4 to isolate "x"



So the first part of the answer is {{{x=3}}}



{{{y=3x-4}}} Go back to the first equation



{{{y=3(3)-4}}} Plug in {{{x=3}}}



{{{y=9-4}}} Multiply



{{{y=5}}} Subtract


So the second part of the answer is {{{y=5}}}


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Answer:



So the solutions are {{{x=3}}} and  {{{y=5}}} which form the ordered pair (3,5)



I'll let you do the check (simply plug in the two solutions and simplify)