Question 550551
"When 18 is subtracted from four times a certain number, the result is 5/2 the original number. " means that we have the equation {{{4n-18=(5/2)n}}}. Let's solve this equation for n.



{{{4n-18=(5/2)n}}} Start with the given equation.



{{{2(4n-18)=2((5/cross(2))n)}}} Multiply both sides by the LCD {{{2}}} to clear any fractions.



{{{8n-36=5n}}} Distribute and multiply.



{{{8n=5n+36}}} Add {{{36}}} to both sides.



{{{8n-5n=36}}} Subtract {{{5n}}} from both sides.



{{{3n=36}}} Combine like terms on the left side.



{{{n=(36)/(3)}}} Divide both sides by {{{3}}} to isolate {{{n}}}.



{{{n=12}}} Reduce.



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Answer:


So the solution is {{{n=12}}} 



So the unknown number is 12