F.2 maths simplify the following (important.plz help)

1)2a-4ab/6bc-3c
= [2a(1-2b)] /3c(2b-1)
=-2a/3c
2)(2a-3/6ab) / (3-2a)/4b
= [(2a-3) (4b)] /[(3-2a) (6ab)]
= -4b / 6ab
= -2/3a
3)(ab+ac/b) / (b^2+bc/ab)
= [(a)(ab) (b^2+c)] / [(b)(b)(ab^2+ c)]
= a^2 (b^2+c) /[b (ab^2+c)]
4)(1/ax+ay)-(1/bx+by )
=1/[a(x+y)] - 1/[b(x+y)
= (b-a)/[ab(x+y)]
5)(x+1/x-1)-(x-1/x+1 )
=[(x+1)^2 - (x-1)^2]/[(x+1)(x-1)]
= [x^2+2x+1 - x^2 +2x-1]/(x^2 - 1)
= 4x/(x^2 - 1)
6)[3/(x-3)(x+1)]-[3/(x-3)(x+4)]
= 3[(x+4) - (x+1)]/[(x-3) (x+4)(x+1)]
=9/(x-3)(x+4)(x+1)