作业帮七年级数学分式的基本性质,
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 01:58:04
七年级数学分式的基本性质,
1.a²+4a+3除以a²+a-6 2.x²+y²-2xy-9除以x²+6x+9-y² 3.x²+x-6除以x^4-13x²+36
1.a²+4a+3除以a²+a-6 2.x²+y²-2xy-9除以x²+6x+9-y² 3.x²+x-6除以x^4-13x²+36
(1)(a^2+4a+3)/(a^2+a-6)=[(a+1)(a+3)]/[(a+3)(a-2)]=(a+1)/(a-2)
(2)(x^2+y^2-2xy-9)/(x^2+6x+9-y^2)
=[(x-y)^2-9]/[(x+3)^2-y^2]
=[(x-y+3)(x-y-3)]/[(x+3+y)(x+3-y)]=(x-y-3)/(x+y+3)
(3)(x^2+x-6)/(x^4-13x^2+36)=[(x+3)(x-2)]/[(x^2-4)(x^2-9)]
=[(x+3)(x-2)]/[(x+2)(x-2)(x+3)(x-3)]
=1/[(x+2)(x-3)]
(2)(x^2+y^2-2xy-9)/(x^2+6x+9-y^2)
=[(x-y)^2-9]/[(x+3)^2-y^2]
=[(x-y+3)(x-y-3)]/[(x+3+y)(x+3-y)]=(x-y-3)/(x+y+3)
(3)(x^2+x-6)/(x^4-13x^2+36)=[(x+3)(x-2)]/[(x^2-4)(x^2-9)]
=[(x+3)(x-2)]/[(x+2)(x-2)(x+3)(x-3)]
=1/[(x+2)(x-3)]