初一诊断卷
一、因式分解
-
\(6x^2-13x+6\)
\(原式=(2x-3)(3x-2)\)
-
\(16mx(a-b)^2-9mx(a+b)^2\)
\(原式=mx[16(a-b)^2-9(a+b)^2]\)
\(=mx[(4a-4b)^2-(3a+3b)^2]\)
\(=mx[(4a-4b+3a+3b)(4a-4b-3a-3b)]\)
\(=mx(7a-b)(a-7b)\)
-
\(4x^2-4xy+y^2+6x-3y-10\)
\(原式=(2x-y)^2+3(2x-y)-10\)
\(=(2x-y+5)(2x-y-2)\)
-
\(x^2-2x+1\)
\(原式=(x-1)^2\)
-
\(x^5+3x^4y-5x^3y^2-15x^2y^3+4xy^4+12y^5\)
\[ \]
\(原式=x^3(x^2+3xy-5y^2)-y^3(15x^2-4xy-12y^2)\)
\=無法解出(x+y)(x+2y)(x+3y)(x+4y)+y^4
\[ \]
\原式=無法解出
二、计算
- \[\frac{2b+3c}{bc}+\frac{2a+2c}{3ac}-\frac{2b+9a}{3ab} \\原式=\frac{6ab+9ac+2ab+2bc-2bc-9ac}{3abc} \\=\frac{8ab}{3abc} \\=\frac{8}{3c} \]
- \[\frac{1}{a-3}-\frac{6}{a^2-9} \\原式= \]