SOLUTION: If today is my birthday, and my age fifteen years ago is the square of my age fifteen years from now, what is my age?

Question 792153: If today is my birthday, and my age fifteen years ago is the square of my age fifteen years from now, what is my age?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!

I think it should read:
my age fifteen years ago squared, is my age fifteen years from now,
what is my age?
:
Let a = your present age
(a-15)^2 = (a+15)
a^2 - 30a + 225 = a + 15
a^2 - 30a - a + 225 - 15 = 0
a^2 - 31a + 210 = 0
Factors to
(a-10)(a-21) = 0
Two solutions
a = 10
a = 21, this is the only solution that makes sense
:
:
Check
(21-15)^2 = 36
21 + 15 = 36
RELATED QUESTIONS
i'm older than my sister. 15 years ago her age was 1/3 of what my age is now. 10 years... (answered by stanbon,josgarithmetic)

fifteen years ago my mom was twice as old as i was. Now her age is just three halves of... (answered by macston,MathTherapy)

If the ratio of my age now to my age 6 years ago is 3:2, then my age 4 years from now... (answered by ewatrrr)

My age was 1/3 of my fathers' age before 18 years ago. Now my fathers' age is twice as my (answered by ikleyn)

Today is my birthday. If my age in months is 99 great than my age in years, how many... (answered by macston,fractalier)

Today my daughter is 1/3 of my age. Five years ago she was 1/4 of my age then. How... (answered by solver91311)

Today my daughter age is one sixth of my age if I was 40 years old 2 years back what is... (answered by josgarithmetic)

10 times my age minus 5 times my brothers age is 100. 10 years ago the square of my age... (answered by ankor@dixie-net.com)

Suppose I am father 4 years ago my daughter age was 1/2 of me now my daughter age is 30... (answered by rfer)