150X+140Y≤3000 (1) X≤Y (2) 3X+2Y=50 (3) 怎样解

150X+140Y≤3000 (1) X≤Y (2) 3X+2Y=50 (3) 怎样解 150X+140Y≤3000 (1) X≤Y (2) 3X+2Y=50 (3)这一题怎样解 详细 (x+y)(x-y)+4(y-1) 设变量x y满足约束条件x-y≥-1 x+y≥1 2x-y≤1 z=(x-2y)/(x+y)的最大值 x=3,y=-x+5(x＞1) y=-x+5(x≤1),y=? 实数x,y满足|x+y|≤1,|x-y|≤1.证明|x|+|y|≤1. 整数x,y满足x^2+y^2+1≤2x+2y,求x+y的值 整数x,y满足不等式x^2+y^2+1≤2x+2y,求x,y的值 [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y 若x²+y²+1≤2x+2y,求x+y.（详解） 作函数y= x (x>0) 1 (-1≤x≤1) -2x (x x>=1,x-y y=x-1(x 计算：(1+ y/x-y )·(1- x/x+y) (x/x+y-x/y-x-2xy/x.x-y.y)/(1/x-1/y) 分式化简 感激不尽1.x,y满足(x-y-1)(x+y) (1-y+x/y)除以y平方-x平方/x 证明:(y/x)+(x/y)+xy≥x+y+1