Question 378904: The square of Janes age 6 years ago is equal to her age in six years time. Find her present age?
Thank you. Found 3 solutions by Alan3354, Jerome952, MathTherapy:Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! (j-6)^2 = j+6
j^2 - 12j + 36 = j+6
j^2 - 13j + 30 = 0
(j-10)*(j-3) = 0
j = 10
j = 3 (gives negative ages)
You can put this solution on YOUR website! Follow correct answer please
let Jane's age now be X
Jane's age 6years ago =X -6
Jane's age in 6years time = X +6
(X -6)^2 = X +6
(X-6)(X-6)=X +6
X^2 -6X-6X +36X= X +6
X^2 -12X +36X-X-6=0
X^2-11X +30=0
the roots are -6 and -5
X^2-6X-5X +30=0
X(X -6)-5(X-6)=0
(X-6)(X-5)=0
X=6 or X=5
since both answers are positive and they satisfy our equation, we take them both
so jane's present age is 5years or 6Years old
