algebra
posted by Lanise on .
A person is 3 times as old as aonther person but in 15 years she will only be 2 times as old. I found the answer the younger person is 15 years old and the older person is 45 years old. But 15 years from now the younger person will be 30 years old and the older person will be 60 years old. I have to come up with an equation for this. I wanted to say y=15x+30 where x is the number of times that the person is older than the younger person and y is the final number of years older. But this doubles the answer and also is totally wrong. Please help.

You got the right answer without using equations. Here is the way to do it with algebra. Let x be the younger person's age now, and y be the older person's age now.
y = 3x
(y + 15) = 2(x + 15)
Now eliminate one variable using algebra.
y = 2x +30 15 = 2x + 15
3x = 2x + 15
x = 15. 
YOU ARE RETART JEWBU