Let a and b be the solutions to 5x^2 - 11x + 4 = 2x^2 - 7x + 9 + 7x^2 - 14x - 11. Find 1/a + 1/b.
Simplify as
4x^2 -10x -6 = 0
2x^2 - 5x - 3 = 0
Product of roots = -3/2 = ab
Sum of roots = 5/2 = a + b
1 / a + 1 / b = (a + b) / (ab) = ( 5/2) /(-3/2) = - 5 / 3