(1)x²-4xy+4y²-10x+20y+25 (2)(n+1)(n+2)(n+3)(n+4)+1第一题都是二次方
来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/24 09:03:25
(1)x²-4xy+4y²-10x+20y+25(2)(n+1)(n+2)(n+3)(n+4)+1第一题都是二次方(1)x²-4xy+4y²-10x+20y+2
(1)x²-4xy+4y²-10x+20y+25 (2)(n+1)(n+2)(n+3)(n+4)+1第一题都是二次方
(1)x²-4xy+4y²-10x+20y+25
(2)(n+1)(n+2)(n+3)(n+4)+1
第一题都是二次方
(1)x²-4xy+4y²-10x+20y+25 (2)(n+1)(n+2)(n+3)(n+4)+1第一题都是二次方
(1)x²-4xy+4y²-10x+20y+25
=x²-2×2xy+(2y)²-(10x-20y)+25
=(x-2y)²-2×5(x-2y)+5²
=(x-2y-5)²
(2)(n+1)(n+2)(n+3)(n+4)+1
=(n+1)(n+4)(n+2)(n+3)+1
=(n²+5n+4)(n²+5n+6)+1
=[(n²+5n)+4][(n²+5n)+6]
=(n²+5n)²+2×5(n²+5n)+24+1
=(n²+5n)²+2×5(n²+5n)+5²
=(n²+5n+5)²
(x-2y-5)²
第二题再加分才行
(1)x²-4xy+4y²-10x+20y+25
=(X-Y)²-5(2X-4Y-5)