1、16(a-b)²+24(b-a)(a+b)+9(b+a)²
=[4(a-b)]²-2*4*3(a-b)(a+b)+[3(b+a)]²
=[4(a-b)-3(a+b)]²
=(a-7b)²
2、(x²+4X+3)(x²+12x+35)+15
=(x+1)(x+3)(x+5)(x+7)+15
=(x²+8x+7)(x²+8x+15)+15
=(x²+8x)²+22(x²+8x)+105+15
=(x²+8x)²+22(x²+8x)+120
=(x²+8x+12)(x²+8x+12)
1、16(a-b)²+24(b-a)(a+b)+9(b+a)²
=[4(a-b)]²-2*4*3(a-b)(a+b)+[3(b+a)]²
=[4(a-b)-3(a+b)]²
=(a-7b)²
2、(x²+4X+3)(x²+12x+35)+15
=(x+1)(x+3)(x+5)(x+7)+15
=(x²+8x+7)(x²+8x+15)+15
=(x²+8x)²+22(x²+8x)+105+15
=(x²+8x)²+22(x²+8x)+120
=(x²+8x+12)(x²+8x+12)