How old is christopher now ?

Say Christopher's current age is x. That means Ishaan's current age is x + 20, because he's 20 years older.

14 years ago, Christopher was x - 14 years old. If Ishaan was 3 times as old, he was 3(x - 14) years old.

We know Ishaan's current age is 14 years more than his age 14 years ago, so we can say 3(x - 14) + 14 = x + 20

Using that equation, we can solve for x, which is Christopher's current age.

3(x - 14) + 14 = x + 20

3x - 42 + 14 = x + 20

3x - 28 = x + 20

2x = 48

x = 24

So, Christopher's current age is 24 years.

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this