4x^2+y^2=16,与5x^2+9y^2=100的图像

  如果x=5分之2y,x与y【 】比例；如果x乘y=9分之4,x与y【 】比例；如果x-y=2  如果x=5分之2y,x与y【 】比例；如果x乘y=9分之4,x与y【 】比例；如果x-y=20,x与y【 】比例. 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 如果x=5分之2y,x与y【 】比例；如果x乘y=9分之4,x与y【 】比例；如果x-y=20,x与y【 】比例. x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 关于X,Y的方程组3X+2Y=2m+5与x-y=4m-5的解x,y满足x+2y 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 x*x+2x+y*y-4y+5=0 x= y= 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 {5(x-3y)-6=2x+1 3(x+6y)+4=9y+19 ｛3分之2（x-y）=4分之x+y-1 6）x+y)=4(2x-y)+16 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 x(y+2)+(4-x)=9与x(y+3)+y(8-x)=14解方程式 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 初二数学平面直角坐标系求两条直线交点的坐标:(1)y=-x+7与y=2/3x-4/3(2)y=3x-4与y=-7x+11(3)y=-1/2x+5/2与y=x+2(4)y=1/3(2x+5)与y=1/9(2x+15) 已知y-2与x+4成正比例 x=3 y=5,则y与x的关系 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? (x-y)/4+(x+y)/5=1/4 (x+y)/9-(x-y)/3=//2(x-y)/4+(x+y)/5=1/4(x+y)/9-(x-y)/3=//2