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2 votes
2 votes
The difference of two numbers is 9. The sum of the two numbers is 15. What are the two numbers?

User Chinyere
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1 Answer

27 votes
27 votes

Let numbers be a and b

  • a+b=15--(1)
  • a-b=9---(2)

Adding both


\\ \qquad\quad\sf\longmapsto 2a=24


\\ \qquad\quad\sf\longmapsto a=(24)/(2)


\\ \qquad\quad\sf\longmapsto a=12

  • Put value in eq(2)


\\ \qquad\quad\sf\longmapsto 12-b=9


\\ \qquad\quad\sf\longmapsto b=12-9


\\ \qquad\quad\sf\longmapsto b=3

User Harry Mallon
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