若|x+y-3|+(2x-y-5)²=0,求xy的值

运用乘法公式计算 :1】（3x-5)²;-（2x+7)²;;【2】（x+y+1)(x+y-1)；【3】（2x-y-3）²【4运用乘法公式计算 :1】（3x-5)²;-（2x+7)²;;【2】（x+y+1)(x+y-1)；【3】（2x-y-3）²【4】(x+2)(x-2)&su 若代数式(2mx²-x²+3x+1)-(5x²-4y²+3x) 的值与x无关求2m&su快速给出解法给100分 化简:5(x-y)+2(x+y)-3(x-y) 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (2x-3y)-(5x-y) (2X-3y)-(5x-y) (2x-5y)(3x+y) 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) ﹙2x²＋ax－y＋6﹚－﹙bx²－3x＋5y－1﹚的值与x无关,求代数式½a²－2b&su 若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) 若x+y分之x-y=3,求式子x+y分之5(x-y)—2(x-y)分之x+y的值 若x-y分之x+y=3,求式子x+y分之5(x-y)—2（x-y）分之x+y的值 (2x+y)²+(x+3y)(x-3y)-x(5x+8y)因式分解 [2(x-y)^5-8(x-y)^2(x+y)+6y(x-y)^2]÷2(x-y)^2[2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2]÷2(x-y)^2 因式分解的一些题 x的三次方—9x+8 （x²—1）（x+3）（x+5）+12 x²+xy—6y²+x+13y—6 m&su些题 (5)若x/2=y/3(y不为0）则x/y=____,x+y/y=___,y/x-y=___. 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值