作业帮 > 数学 > 作业

八下数学分解因式的题(m+n)²-n² 49(a-b)²-16(a+b)² (2

来源:学生作业帮 编辑:拍题作业网作业帮 分类:数学作业 时间:2024/04/27 19:14:25
八下数学分解因式的题
(m+n)²-n²
49(a-b)²-16(a+b)²
(2x+y)²-(x+2y)²
1/3m²-3n²
(a+b)²-(a-b)²
(9a+4b)²-(3a-b)²
(m+n)²-n²
=(m+n+n)(m+n-n)
=m(m+2n)
49(a-b)²-16(a+b)²
[7(a-b)+4(a+b)][7(a-b)-4(a+b)]
=(11a-3b)(3a-11b)
(2x+y)²-(x+2y)²
=[(2x+y)+(x+2y)][(2x+y)-(x+2y)]
=(3x+3y)(x-y)
=3(x+y)(x-y)
1/3m²-3n²
=1/3(m²-9n²)
=1/3(m+3n)(m-3n)
(a+b)²-(a-b)²
=[(a+b)+(a-b)][(a+b)-(a-b)]
=2a×2b
=4ab
(9a+4b)²-(3a-b)²
=[(9a+4b)+(3a-b)][9a+4b)-(3a-b)]
=(12a+3b)(6a+5b)
=3(4a+b)(6a+5b)