Wednesday, November 5, 2014

The greater of two numbers is 5 more than the smaller. If the smaller is added to twice the greater, the result is 22. Find both of the numbers.

Hello!


Denote the smaller number as `x` and the greater as `y.` Then it is given that


`y=x+5`  ("the greater of two numbers is 5 more than the smaller")


and


`x+2y=22`  ("if the smaller is added to twice the greater, the result is 22").



This is the simple system of two linear equations with two variables. Substitute `y` from the first equation into the second and obtain


`x+2(x+5)=22,` or `3x+10=22,` or `3x=12,` `x=4.`


And recall `y=x+5=9.`



So the answer is: the smaller number is 4, the greater is 9.

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