x/y=4 (x-13)/(y+13)=7/5
1.x+x+x+y+y=6.4 y+y+y+x+x=7.1 x= ( ) y=( ) 2.1,4,7,10,13……这串
2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X
(1)7x+3y=18 2x+3y=13 (2)5x+2y=7 2x+y=1 (3)3x+4y=5 4x+5y=6如题
用代入法 1,x-y=4 4x+2y=-1 2,x-y=13 x=6y-7 3,5x-y=110 9y-x=110
二元一次方程组的解.2X-4Y=6 3X+2Y=172X+3Y=73X-5Y=13Y=X+52X+5Y=233X+5Y=
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
x-y=13 x=6y-7
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
已知:4x = 5y,求(x+y) :y
已知x,y满足:x平方+y平方-4x+6y+13=0求(3x+y)-3(3x-y)(x+y)-(x-3y)(x+3y)=