1.1/2:1/5=1/4:x2.0.8:4=x:83.3/4:x=3:124.36/x=54/35.2/9=8/x6.1.25:0.25=x:1.6

2^5+5x2^4+10x2^3+10x2^2+5x2+1 已知x2－4x+1=0,求x2／(x2)2－3x2+1 1/(x2+x)+1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=4/21x2是x的平方 4x2.5x2+4x2×2+2x2.5x2= 计算:x2-5x+6/x2-4x+3 + x2-4x+3/x2-2x+1 + x2-3x-4/1-x2 若 x2-3x+1=0,求（2x2×x3-5x2×x2+2 x3-8x2 ）÷（x2+1 ）的值 x2-5x+1=0则x2+x2/1 用excel解 （1）maxz=2x1+2x2 (2)maxz=X1+X2 (3)maxz=10x1+5x2 (4)maxz=2x1+x2 （5）maxz=3x1+5x2（1）maxz=2x1+2x2 x1-x2>=-1-0.5x1+x2=0(2)maxz=X1+X2 x1-x2>=03x1-x2=0(3)maxz=10x1+5x23x1+4x2 (1-x2)(x2-4x+5) 不等式（x2-4x-5)(x2+1) 4x2-(x2+1)2因式分解 已知x2+5x-4=0,求x3+6x2+x+2的值已知x2+x-1=0,求x3+2x2+3的值 用杨辉三角规律计算下题 2^5-5x2^4+10x2^3-10x2^2+5x2-1 求和Sn=1x2+3x2^2+5x2^3+…+（2n-1）x2^n Sn=1x2+3x2^2+5x2^3+...+（2n-1）2^n 3/x2 -3x+2-1/x-2=1/x2 -x+4/x2 -2x 1+2x2+3x2^2+4x2^3+.+nx2^n-1=? 1+2x2+3x2^2+4x2^3+.+nx2^n-1=?