Factor everything: x2 - 8x - 20 = (x - 10)(x + 2) x2 + 3x - 4 = (x + 4)(x - 1)
x2 - x - 6 = (x - 3)(x + 2) x2 + 10x + 24 = (x + 4)(x + 6)
Cancelling the like factors: (x - 10) / (x - 3) - (x - 1) / (x + 6)
Getting the common denominator of (x - 3)(x + 6)
[ (x - 10)(x + 6) / [ (x - 3)(x + 6) ] - [ (x - 1)((x - 3) ] / [ (x - 3)(x + 6) ]
[ (x - 10)(x + 6) - (x - 1)((x - 3) ] / [ (x - 3)(x + 6) ]
[ (x2 - 4x - 60) - (x2 - 4x + 3) ] / [ (x - 3)(x + 6) ]
[ -63 ] / [ (x - 3)(x + 6) ]