(x^2-x-2)(x^2+11x+28)-19用换元法

来源：学生作业帮助网编辑：作业帮时间：2024/05/01 07:14:30

(x^2-x-2)(x^2+11x+28)-19用换元法
(x^2-x-2)(x^2+11x+28)-19
用换元法

(x^2-x-2)(x^2+11x+28)-19用换元法
(x^2-15x+54)(x^2+11x+28)+350
=(x-6)(x-9)(x+4)(x+7)+350
=[(x-6)(x+4)][(x-9)(x+7)]+350
=(x^2-2x-24)(x^2-2x-63)+350
设u=x^2-2x,则
(x^2-2x-24)(x^2-2x-63)+350
=(u-24)(u-63)+350
=u^2-87u+1862
=(u-38)(u-49)
=(x^2-2x-38)(x^2-2x-49)
=(x-1+√39)(x-1-√39)(x-1+5√2)(x-1-5√2)

=(x-2)(x+1)(x+4)(x+7)-19
=[(x-2)(x+7)][(x+1)(x+4)]-19
=[(x^2+5x)-14][(x^2+5x)+4]-19
=(x^2+5x)^2-10(x^2+5x)-56-19
=(x^2+5x)^2-10(x^2+5x)-75
=(x^2+5x-15)(x^2+5x+5)

300字读后感 2篇俄把格式说一下吧：《xxxx》（写题目）主要内容：x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x(写那篇文章的主要内容）思考分析：x x x *-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X || 分解因式：x*x*x*x+2*x*x*x-9*x*x-2x+8 x(x*x-6x-9)-x(x*x-8x-15)+2x(3-x) 填九宫格帮帮忙.x x 6 x x 7 x x 98 x x x 3 x 1 x x 9 x x 6 x 5 x 3 x x x 3 x x x x 1 8x x x 9 x 1 x x x2 1 x x x x 6 x x x 6 x 7 x 3 x x 1 x x 9 x 2 x x x 47 x x 8 x x 5 x x 七年级下册政治复习提纲(山东人民出版社)第五单元是青春的脚步青春的气息别弄错了啊!格式：X X X X X X X X X 1、X X X X X X X X X X.2、X X X X X X X X X.3、X X X X X X X X X X X. (x/x-2-x/x+2)/4x/x-2 分解因式----（X*X-X)(X*X-X-2)+1 |-x|+|x+2|-|2-x| x(x-2)(x-3) {x|(x+3)(x-2) -x^3+x^2-x 已知x*x+x-1=0 求x*x*x-2x+11=? x×x+3x-9/ x+2 f(x)=x^2+x (x |x|-2/x*x-x-12 x+2x+3x+.+100x 】x(x+1)+x^2(x-1)