The answer is 37 years old.
I = -425x² + 45500x -650000
I = 450000
-425x² + 45500x -650000 = 450000
-425x² + 45500x - 650000 - 450000 = 0
-425x² + 45500x - 1100000 = 0
Divide all factors by 25:
- 17x² + 1820x - 44000 = 0
This is quadratic equation (ax² + bx + c = 0)

Since, the youngest age is needed, the correct answer is x = 37
the answer is simple and easy. why do you ask such question.
anyway answer is D i.e. 6l²(6*7*7)
The equation of a line that passes through (x1,y1) and has a slope of m is
y-y1=m(x-x1)
given
y-(-4)=-5(x-3)
the point is (3,-4)
The solution to this equation is 1=2