This problem is adding and subtracting rational espressions with different denominators.
4x/[2x^2 + x -10] - 9x/ [x^2 + x - 6] Factor the denoms -->
Factoring is a process of un-FOILing:
2x^2 + x -10 = (2x +5)(x-2)
x^2 + x - 6 = (x+3)(x-2)
Since both denoms include (x-2), we need it just once as a factor for the common denom -- (2x+5)(x-2)(x+3)
Now multiply each fract ion by the common denom to find the new numerators. Combine the new numerators and keep the common denom.