y=(3x³-3x²)/(3-4x²)
y'=((9x²-6x)(3-4x²)-(3x³-3x²)(-8x))/(3-4x²)²=
(27x²-36x⁴-18x+24x³+24x⁴-24x³)/(3-4x²)²=
(27x²-12x⁴-18x)/(3-4x²)²
y=(3x³-3x²)/(3-4x²)
y'=((9x²-6x)(3-4x²)-(3x³-3x²)(-8x))/(3-4x²)²=
(27x²-36x⁴-18x+24x³+24x⁴-24x³)/(3-4x²)²=
(27x²-12x⁴-18x)/(3-4x²)²