SOLUTION: one number is 3 less than another. their sum is 15. find the numbers. this is a word problem i got x-3x=15 but it does not come out to the answers. the answers are 9,6. i have

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: one number is 3 less than another. their sum is 15. find the numbers. this is a word problem i got x-3x=15 but it does not come out to the answers. the answers are 9,6. i have       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 258515: one number is 3 less than another. their sum is 15. find the numbers. this is a word problem i got x-3x=15 but it does not come out to the answers. the answers are 9,6. i have no idea how to set it up>
Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
Let X = first number and Y = second number
"one number is 3 less than another" translates to
(i) X = Y - 3
"their sum is 15" translates to
(ii) X + Y = 15
solve by substitution to get
(iii) Y - 3 + Y = 15
solving for Y we get
2Y - 3 = 15
2Y = 18
Y = 9
So,
X = 6
We have (X,Y) = (6,9)