(X+3)/(X^2-9)+X/(6+X-X^2)*(3-X)/(4X-6)
=(X+3)/(X-3)(X+3)-X/(X^2-X-6)*(3-X)/(4X-6)
=1/(X-3)-X/(X-3)(X+1)*(3-X)/(4X-6)
=1/(X-3)+X/(X-3)(X+1)*(X-3)/(4X-6)
=1/(X-3)+X/(X+1)*1/(4X-6)
=1/(X-3)+X/[(X+1)(4X-6)]
=[(X+1)(4X-6)]/[(X+1)(4X-6)(X-3)]+X(X-3)/[(X+1)(4X-6)(X-3)]
=[(X+1)(4X-6)+X(X-3)]/[(X+1)(4X-6)(X-3)]
=(4X²+2X-6+X²-3X)]/[(X+1)(4X-6)(X-3)]
=(5X²-X-6)]/[(X+1)(4X-6)(X-3)]
=(5X-6)(X+1)/[(X+1)(4X-6)(X-3)]
=(5X-6)/[(4X-6)(X-3)]