tolong ya kak buatin ini,klo bisa cpetan yaa

a). 1/a+3/ab = b+3/ab
b). 3/x-4 - x/x²-3x-4
= 3/(x-4) - x/(x-4)(x+1)
= 3(x+1)-x / x²-3x-4 = 3x+1-x/x²-3x-4
= 2x+1 / x²-3x-4
c). 2/x+2 - 3/x-4 = 2(x-4) - 3(x+2) /x²-2x-8
= 2x-8-3x-6 / x²-2x-8
= -x-14 / x²-2x-8