因式分解化简求值习题大量大量大量的!每天十道因式分解,十道化简求值大神的力量是伟大的

因式分解化简求值习题大量大量大量的!每天十道因式分解,十道化简求值大神的力量是伟大的

1.化简(1-1/x-1)/(x/x^-1)在选择一个适当的x求值解(1-1/(x-1))/(x/(x^-1))=((x-2)/(x-1))/(x/(x+1)(x-1))=(x-2)/(x-1)*(x+1)(x-1)/x=(x-2)(x+1)/x当x=2时,原式=0x适当的值一定不能是1,-1,02.、1/2(x+y+z)方+1/2(x-y-z)(x-y+z)-z(x+y),其中x-y=6,xy=21.要详细步骤 化简得： 1/2(x+y+z)方+1/2(x-y-z)(x-y+z)-z(x+y)= 1/2[(x+y)方+2z(x+y)+z方]+1/2[(x-y)方-z方]-z(x+y)= 1/2(x+y)方+1/2(x-y)方=x方＋y方 由x-y=6,xy=21得,x方＋y方＝（x-y）方＋2xy＝78 3. 9x+6x^2 -3(x-2/3x^2).其中x=-2 9x+6x² -3(x-2/3x²) =9x+6x²-3x+2x² =8x²+6x =8×(-2)²+6×(-2) =32-12 =20 4. 9x+6x^2 -3(x-2/3x^2).其中x=-2 9x+6x² -3(x-2/3x²) =9x+6x²-3x+2x² =8x²+6x =8×(-2)²+6×(-2) =32-12 =20 5.1/4(-4x^2+2x-8)-(1/2x-1),其中x=1/2 1/4(-4x²+2x-8)-(1/2x-1) =-x²+1/2x-2-1/2x+1 =-x²-1 =-(1/2)²-1 =-1/4-1 =-5/4 6. 3x'y-[2x'y-(2xyz-x'z)-4x'z]-xyz,其中x=-2,y=-3,z=1, :3x'y-[2x'y-(2xyz-x'z)-4x'z]-xyz =3x'y-2x'y+2xyz-x'z+4x'z-xyz =x'y-xyz+3x'z =4*(-3)-2*3*1+3*4*1 =-12-6+12 =-6 7. (5a^2-3b^2)+(a^2+b^2)-(5a^2+3b^2),其中a=-1,b=1 =5a^2-3b^2+a^2+b^2-5a^2-3b^2 =a^2-5b^2 =(-1)^2-5*1^2 =1-5 =-4 8. 2(a^2b+ab^2)-2(a^2 b-1)-2ab^2 -2其中a=-2,b=2 =2a^2b+2ab^2-2a^2b+2-2ab^2-2 =0 9. 、(X-2分之1Y-1)(X-2分之1Y+1)-(X-2分之1Y-1)的平方 其中X=1.7,Y=3.9(先化简再求值) [(X-2分之1Y)-1][(X+2分之1Y)+1]-(X-2分之1Y-1)平方 =(X+2分之1Y)平方-1-(X-2分之1Y)平方+2(X-2分之1Y)-1 =(X+2分之1Y)平方-(X-2分之1Y)平方+2(X-2分之1Y)-2 =2XY+2X-Y-2 =3.9*2.4+1.4 =10.76 10. 先化简再求值,1/2a-(2a-2/3b^2)+(-3/2a+2b^2)其中a=-2,b

哦，回答的不错