Question 1019924
The amount of John's savings after x weeks is 60 + 5x, while that of Sarah's is {{{x^2 + 46}}}.

To make their savings equal in value, let {{{x^2 +46 = 60 + 5x}}}
==> {{{x^2 - 5x -14 = 0}}}
==> (x-7)(x+2) = 0
==> x = 7 or x = -2.
x = -2 is unacceptable as a solution.
Therefore it will take 7 weeks for John's and Sarah's savings to become equal.