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zhazen
Feb 4, 2010, 08:12 PM
Math problem A is 4 yrs older than B in 7 years the sum of their ages will be 70. How old are they now?

amy99roo
Feb 5, 2010, 12:17 AM
Sounds like algebra
Use two equations and substitute the variables into the other:

Equation 1: B+4= A
Equation 2: A+B+7= 70

Now substitute equation 1 into equation 2:

(B+4)+B+7= 70

Combine like terms and solve for B:

2B+11= 70
2B= 70-11
2B= 59
B= 59/2
B= 29.5

Plug B into equation 1 and solve for A:

29.5+4= A
A= 33.5

Check with equation 2:
A+B+7=70
33.5+29.5+7= 70

Unknown008
Feb 5, 2010, 11:55 AM
A is older than B.

This means that the age of A is greater than that of B.

A - 4 = B

(If you removed 4 years from A, both would be of the same age)

Then, 7 years later, A would be (A+7) and B would be (B+7), making a total of

(A+7) + (B+7) = 70

You can simplify to : A + B + 14 = 70, then to A + B = 56.

From
A + B = 56 and
A - 4 = B, you can substitute B:

A + (A - 4) = 56
2A - 4 = 56
2A = 60
A = 30

Then, (30 - 4) = B
So, B = 26.

Check, today, A is 30 and B is 26. So, A is indeed 4 years older than B.
In seven year's time, A will be 37 and B will be 33. Sum is 70!

Answers:
A = 30
B = 26

amy99roo
Feb 5, 2010, 12:12 PM
So much for that engineering degree! Ha ha!

Unknown008
Feb 5, 2010, 12:15 PM
Don't worry, now that you found your mistake, I doubt you'll repeat a similar one again :)

MsMewiththat
Feb 5, 2010, 12:16 PM
Lucky kid just got their homework done! LOL

amy99roo
Feb 5, 2010, 12:17 PM
Somehow I doubt it! F in math for me! Computers calculators and reports make you dumber!

Unknown008
Feb 5, 2010, 12:22 PM
How about asking the OP another question and make him/her answer and post his/her answer? ;)