6. Find the HCF and LCM of: (b) (a) 4(a²-4), 6(a²-a-2) and 12(a² + 3a-10) 2x²-3xy-2y², 6x² + xy - y² and 3x² - 7xy + 2y² (c) a(c + a)-b(b + c), b(a + b)-c(c + a) and c(b + c)-a(a + b) (d) p² +q²+2pq-1, q²-p² + 2q + 1 and p² - q² + 2p + 1 (e) 6x²-5x-4, 8x² + 2x - 15 and 12x²-43x +35