(1)填空5x^2-6x+1( )=7x+8 (2)若(ax^2-2xy+y^2)-(-x^2+bxy+2y^2)=5x^2-9xy+cy^2,则a=( ),b=( )c=( ).(3)已知方程(m^2-4)-x^2-(m-2)x+3=0是关于x的一元一次方程,则(1+m)^2005的值为( ).(4)若代数式(2x^2+ax-y+6)-(2bx^2-3
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/14 08:07:34
![(1)填空5x^2-6x+1( )=7x+8 (2)若(ax^2-2xy+y^2)-(-x^2+bxy+2y^2)=5x^2-9xy+cy^2,则a=( ),b=( )c=( ).(3)已知方程(m^2-4)-x^2-(m-2)x+3=0是关于x的一元一次方程,则(1+m)^2005的值为( ).(4)若代数式(2x^2+ax-y+6)-(2bx^2-3](/uploads/image/z/1855890-18-0.jpg?t=%281%29%E5%A1%AB%E7%A9%BA5x%5E2-6x%2B1%28+%29%3D7x%2B8+%EF%BC%882%EF%BC%89%E8%8B%A5%EF%BC%88ax%5E2-2xy%2By%5E2%29-%28-x%5E2%2Bbxy%2B2y%5E2%29%3D5x%5E2-9xy%2Bcy%5E2%2C%E5%88%99a%3D%28+%29%2Cb%3D%28+%29c%3D%28+%29.%283%29%E5%B7%B2%E7%9F%A5%E6%96%B9%E7%A8%8B%EF%BC%88m%5E2-4%29-x%5E2-%28m-2%29x%2B3%3D0%E6%98%AF%E5%85%B3%E4%BA%8Ex%E7%9A%84%E4%B8%80%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%2C%E5%88%99%EF%BC%881%2Bm%29%5E2005%E7%9A%84%E5%80%BC%E4%B8%BA%EF%BC%88+%EF%BC%89.%EF%BC%884%EF%BC%89%E8%8B%A5%E4%BB%A3%E6%95%B0%E5%BC%8F%EF%BC%882x%5E2%2Bax-y%2B6%29-%282bx%5E2-3)
(1)填空5x^2-6x+1( )=7x+8 (2)若(ax^2-2xy+y^2)-(-x^2+bxy+2y^2)=5x^2-9xy+cy^2,则a=( ),b=( )c=( ).(3)已知方程(m^2-4)-x^2-(m-2)x+3=0是关于x的一元一次方程,则(1+m)^2005的值为( ).(4)若代数式(2x^2+ax-y+6)-(2bx^2-3
(1)填空5x^2-6x+1( )=7x+8 (2)若(ax^2-2xy+y^2)-(-x^2+bxy+2y^2)=5x^2-9xy+cy^2,则a=( ),b=( )c=( ).(3)已知方程(m^2-4)-x^2-(m-2)x+3=0是关于x的一元一次方程,则(1+m)^2005的值为( ).(4)若代数式(2x^2+ax-y+6)-(2bx^2-3x+5y-1)的值与字母x的取值无关,求代数式3(a^2-2ab-b^2)-(4a^2+ab+b^2)的值
(1)填空5x^2-6x+1( )=7x+8 (2)若(ax^2-2xy+y^2)-(-x^2+bxy+2y^2)=5x^2-9xy+cy^2,则a=( ),b=( )c=( ).(3)已知方程(m^2-4)-x^2-(m-2)x+3=0是关于x的一元一次方程,则(1+m)^2005的值为( ).(4)若代数式(2x^2+ax-y+6)-(2bx^2-3
(1)填空5x^2-6x+1( -5x2+13x+8 )=7x+8
5x2-6x+(-5x2+13x+8)=7x+8
(2)若(ax^2-2xy+y^2)-(-x^2+bxy+2y^2)=5x^2-9xy+cy^2,则a=( 4 ),b=( 7 )c=( -1 ).
原式=2ax-2xy+2y-(-2x+bxy+4y)=10x-9xy+2cy
(2a+2)x-(2+b)xy-2y=10x-9xy+2cy
所以2a+2=10,2+b=9,-2=2c,所以a=4,b=7,c=-1.
(3)已知方程(m^2-4)-x^2-(m-2)x+3=0是关于x的一元一次方程,则(1+m)^2005的值为( ).
(4)若代数式(2x^2+ax-y+6)-(2bx^2-3x+5y-1)的值与字母x的取值无关,求代数式3(a^2-2ab-b^2)-(4a^2+ab+b^2)的值
(2x^2+ax-y+6)-(2bx^2-3x+5y-1)=2x2+ax-y+6-2bx2+3x-5y+1=(2-2b)x2+(3+a)x-6y+7,又因为与x值无关,所以2-2b=0,3+a=0,所以b=1,a=-1.
-5x^2+13x-8
a=4, b=7,c=-1
-1
-34