You have a system of equations here: "Difference" means to subtract. "Is" means equal. "Sum" means add.
Let X= one number let Y= the other number
X-Y = 12 You have a "-Y" and a "+Y," so just add the two equations together to eliminate one variable (Y).
2X = 144 Divide both sides of the equation by the number next to "X," and you'll have X=________.
Next, substitute the value for "X" into one of the equations to find the value for "Y," and you are done.
However, it would be nice if you checked your work by substituting the values for "X" and for "Y" into both equations to see if you get 12=12 and 132=132, which are true statements making the "X" and "Y" values correct.
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