In the problem it said
Let F(x) be the real-valued function defined for all real x except for x=1 and x=2
turn this into: 7x^2 + 8x - h = 0
using the quadratic formula to find the solutions:\({-8 \pm \sqrt{64+28h} \over 14}\)
this means that \(\sqrt{64+28h}\) = 0
h = \(-\)\(16\over 7\)
The ratio can be expressed as 9x:2x:5x. we get the equation:
\(9x*2+2x*5+5x*10-9*\frac{4}{9}x*2-50=300\)
Simplifying it we get:
\(18x+10x+50x-8x=350\)
\(70x=350\)
Soving it we get x=5. This means that there are \(5*5=\boxed{25}\) $10 notes
a=3 b=2