SOLUTION: I need help! I don't know how to make a formula for this word problem: Two numbers are in the ratio of 7 to 10. If 24 is added to each number, the resulting numbers are in the

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Question 90287: I need help!
I don't know how to make a formula for this word problem:
Two numbers are in the ratio of 7 to 10. If 24 is added to each number, the resulting numbers are in the ratio of 1 to 2. Find the smaller of the two original numbers.

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!

I don't know how to make a formula for this word problem: 
Two numbers are in the ratio of 7 to 10. If 24 is added
to each number, the resulting numbers are in the ratio 
of 1 to 2. Find the smaller of the two original numbers.

Two numbers are in the ratio of 7 to 10

x%2Fy = 7%2F10

which becomes upon cross-multiplying:

10x = 7y

If 24 is added to each number, the resulting numbers
 are in the ratio of 1 to 2

%28x%2B24%29%2F%28y%2B24%29 = 1%2F2

which becomes upon cross-multiplying:

2%28x%2B24%29 = 1%28y+%2B+24%29

2x%2B48 = y+%2B+24

2x+-+y = -24

So we have this system of equations:

10x = 7y
2x+-+y = -24

Solve that system of equations and the answer is

x = -42 and y = -60

The smaller is -60, because the SMALLER of two NEGATIVE
numbers is always the one with the LARGER absolute value.

So the answer is -60

Let's check: with the words:

-42 and -60 are in the ratio of 7 to 10 because the fraction
%28-42%29%2F%28-60%29 reduces to 7%2F10 

If 24 is added to each number, we get -42+24 or -18, and
-60+24 or -36

-18 and -36 are in the ratio of 1 to 2 because the fraction
-18%2F-36 reduces to 1%2F2

Edwin