X^2-9/x^2-4 х/x^2+9 8-4x/(3-x)^2 найти производную

1
[(x²-9)/(x²-4)]`=(2x³-8x-2x³+18x)/(x²-4)²=10x/(x²-4)²
2
[x/(x²+9)]`=(x²+9-2x²)/(x²+9)²=(9-x²)/(x²+9)²
3
[(8-4x)/((3-x)²]`=[-4(3-x)²+2(3-x)(8-4x)]/(3-x)^4=2(3-x)(-12+4x+8-4x)/)3-x)^4=
2(3-x)(-4)/(3-x)^4=-8/(3-x)³