2/5x2/4=?

4x2.5x2+4x2×2+2x2.5x2= 2/5x2/4=? 解分式方程:2/x2+5x+6 + 3/x2+x-6=4/x2-4 4x2-3y2+2xy-4x2+5x2 2+5x2+5x2=? maxz=2x1+x2,5x2 1/(x2+x)+1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=4/21x2是x的平方 mathematica如何求解含有三角函数的方程?FindRoot[{3 x1^3 + 2 x2 - 5 + Sin[x1 - x2] Sin[x1 + x2] == 0,-x1*Exp[x1 - x2] + x2 (4 + 3 x2^2) + 2 x3 + Sin[x2 - x3] Sin[x2 + x3] - 8 == 0,-x2*Exp[x2 - x3] + 4 x3 - 3 ==0},{x1,Pi/2},{x2,2},{x3,0}] 5X2+4=? 2^5+5x2^4+10x2^3+10x2^2+5x2+1 5x2—[x2+(4x—x2)—2(x2—3x)] 已知x2－4x+1=0,求x2／(x2)2－3x2+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 x2+5x+6/2+4-x2/4+x2+x-6/3=0 解方程,检验! 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 max Z=2X1+4X2-5X3 X1+X2+X3=7 2X1-3X2+X3≥10 X1.X2.X3≥0 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