七下数学计算、因式分解题(速回,急)计算:(x^2y-9y)÷(xy+3y) 因式分解:1.6x^2y^2-0.9z^2a^2n+1-ab^2n-(x-2)^2-(x+1)^216m^3n-4mn-1/2×a^2+2b ^29(m+2n)^2-(2m-n)^2-(3/7)^2+(9又7分之4)^2若y-x+z=-4,x^2-(y+z)^2=8,
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/05 12:57:32
![七下数学计算、因式分解题(速回,急)计算:(x^2y-9y)÷(xy+3y) 因式分解:1.6x^2y^2-0.9z^2a^2n+1-ab^2n-(x-2)^2-(x+1)^216m^3n-4mn-1/2×a^2+2b ^29(m+2n)^2-(2m-n)^2-(3/7)^2+(9又7分之4)^2若y-x+z=-4,x^2-(y+z)^2=8,](/uploads/image/z/11633228-44-8.jpg?t=%E4%B8%83%E4%B8%8B%E6%95%B0%E5%AD%A6%E8%AE%A1%E7%AE%97%E3%80%81%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%E9%A2%98%EF%BC%88%E9%80%9F%E5%9B%9E%2C%E6%80%A5%EF%BC%89%E8%AE%A1%E7%AE%97%EF%BC%9A%28x%5E2y-9y%29%C3%B7%28xy%2B3y%29+%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%EF%BC%9A1.6x%5E2y%5E2-0.9z%5E2a%5E2n%2B1-ab%5E2n-%EF%BC%88x-2%EF%BC%89%5E2-%28x%2B1%29%5E216m%5E3n-4mn-1%2F2%C3%97a%5E2%2B2b+%5E29%EF%BC%88m%2B2n%EF%BC%89%5E2-%EF%BC%882m-n%EF%BC%89%5E2-%EF%BC%883%2F7%EF%BC%89%5E2%2B%289%E5%8F%887%E5%88%86%E4%B9%8B4%29%5E2%E8%8B%A5y-x%2Bz%3D-4%2Cx%5E2-%28y%2Bz%29%5E2%3D8%2C)
七下数学计算、因式分解题(速回,急)计算:(x^2y-9y)÷(xy+3y) 因式分解:1.6x^2y^2-0.9z^2a^2n+1-ab^2n-(x-2)^2-(x+1)^216m^3n-4mn-1/2×a^2+2b ^29(m+2n)^2-(2m-n)^2-(3/7)^2+(9又7分之4)^2若y-x+z=-4,x^2-(y+z)^2=8,
七下数学计算、因式分解题(速回,急)
计算:(x^2y-9y)÷(xy+3y) 因式分解:1.6x^2y^2-0.9z^2
a^2n+1-ab^2n
-(x-2)^2-(x+1)^2
16m^3n-4mn
-1/2×a^2+2b ^2
9(m+2n)^2-(2m-n)^2
-(3/7)^2+(9又7分之4)^2
若y-x+z=-4,x^2-(y+z)^2=8,则x+y+z=?
(x^2y-9y)÷(xy+3y)
--------------------------------------------------------------------------
希望大虾速回速回.十点四十分以后不要.(最多十点五十分.速回速回)
16m^3n-4mn打错了
应该是16m^3×n-4mn^3
七下数学计算、因式分解题(速回,急)计算:(x^2y-9y)÷(xy+3y) 因式分解:1.6x^2y^2-0.9z^2a^2n+1-ab^2n-(x-2)^2-(x+1)^216m^3n-4mn-1/2×a^2+2b ^29(m+2n)^2-(2m-n)^2-(3/7)^2+(9又7分之4)^2若y-x+z=-4,x^2-(y+z)^2=8,
计算:(x^2y-9y)÷(xy+3y) =Y(x^2-9)/[(x+3)Y]=X-3
1.6x^2y^2-0.9z^2=0.1(16x^2y^2-9z^2)=0.1(4XY+3z)(4XY-3z)
a^2n+1-ab^2n=a(a^2n-b^2n)=a(a^n+b^n)(a^n-b^n)
-(x-2)^2-(x+1)^2=-X^2+4X-4-X^2-2X-1=-2X^2+2X-5=-2(x-1/2)^2-9/2=
16m^3*n-4mn=4mn(4m^2-1)=4mn(2m+1)(2m-1)
-1/2×a^2+2b ^2=1/2*(4b^2-a^2)=(2b+a)(2b-a)/2
9(m+2n)^2-(2m-n)^2=[3(m+2n)+(2m-n)][3(m+2n)-(2m-n)]=(5m+4n)(m+5n)
-(3/7)^2+(9又7分之4)^2=(43/7)^2-(3/7)^2=(43/7+3/7)(43/7-3/7)=46*40/49
若y-x+z=-4,x^2-(y+z)^2=8,则x+y+z=?
x^2-(y+z)^2=(x+y+z)(x-y-z)=8
y-x+z=-4,x-y-z=4,则x+y+z=8/4=2
(x^2y-9y)÷(xy+3y)=Y(x^2-9)/[(x+3)Y]=X-3