(10+x)x7/2-(10-x)x7/2=28如何解方程

(10+x)x7/2-(10-x)x7/2=28如何解方程 4x+3 x7/10=13/2 3.236x(-7)+(-3.264)x7-(-2.5)x7 解方程：5x-3x7/10=5/7 不等式3-7x7 B x-7 Dx>-10 解方程x+2 x7=28 3分之1X—10=(X+10)x7分之1等于几 4x+(20.8-x)X7的解 (-2)x7与7x(-2)是什么关系 2X/1x3+2X/3x5+2X/5x7+2x/7x9+2x/9x11=10 x=? （4.5-x）X7=17. 8x-6x7=18 Min Z= X1 +X2 +X3 +X4 +X5 +X6 +X7 +X8S.T.2X1 +X2 +X3 +X4 =1002X2 +X3 + 3X5 +2X6 + X7 =100X1 + X3 + 3X4 +2X6 +3X7 +4X8 =100X1,X2,X3,X4,X5 ,X6,X7,X8 >=0经过计算的最优解是X*= (40 ,20,0,0,0 ,30 ,0 ,0)T Z* =90但该解也是最优解X*= (10 ,50,0 解方程2＋2x/1X3+2x/3X5+2x/5X7+2x/7X9=10 1/1X3 + 1/3X5 + 1/5X7 + .+ 1/(2x-1)(2x+1)=10/21(x为整数）x为正整数 7(x一3.6)=5.6 (x+2.8)÷2.5=10 3(x一2.7)=12 4x7十7(x一3.6)=5.6 (x+2.8)÷2.5=10 3(x一2.7)=12 4x7十3x=88 (50一2x)÷2=12 解方程：(10+y)x7/12=2+y （x-10）x7/8=56 x除（1+3/5）=13/4 要计算过程