ANSWER
The equation of the new parabola is

EXPLANATION
The given parabola has equation:

If this parabola is reflected in the x-axis, its equation becomes :

When this parabola is scaled vertically by a factor of 5, the equation becomes,

The 3 in 350 is in the hundred place and in 403 the 3 is in the ones place
If you expand out the brackets you get this,
(4+5i)(a+2i) = 4a + (5a)i + 8i - 10
The -10 comes from 5i * 2i.
Squaring i becomes -1.
Let's group the real stuff together,
and imaginary separately,
(4a - 10) + (5a + 8)i
For this to be purely imaginary,
the real part needs to be zero.
Therefore 4a - 10 = 0
Solve for a.
1. 100 * 20
2. 7 hours
3. 141 kilometers
4. 8.5 hours
5. 55.75 mi/h