{5(2/3+y)-8(x-3)=20
2(x-y)+3(x+y)2-5(x-y)-8(x+y)2-(x-y)
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
若3x-5y=0,则x+y/x=(),x-y/y=(),2x-3y/2x+3y=( )
(1)﹛2x-y=5 (2) 4x-y=1 (3)5x+y=2 7x-3y=20 y=2x+3 x-3y=4 (4)3x
1.((y+2x)(-2x+y)+4(x+2y)^2)/3y 2.(2(x-y)^3-8(x-y)^2(x+y)+6y(
10/x+y+3/x-y=-5 15/x+y-2/x-y=-1(用换元法解此方程组)
用加减消元法(1)2x-y=8 2x+5y=-4 (2)2x+5y=17 2x-3y=1 (3)x-y=5 2x+3y-
用代入法解下列方程组:(1)y=3x 16x-y=18 (2)3x+y=8 3x-y=4 (3)x+5y=5 2x-5y
数学二元一次方程 (x-y=2,2x+y=4 ) (x-y=1,3x-y=5) (x-y=8,3x+y=12 ) (a+
化简求值8x的平方-5x(4y-x)+4x ×(-4x+5/2y)x=1 y=3
(3x+2y-20)的平方 + |4x-5y-19| = 0 ,则x=?y=?
若|3x-y-7|+(5x+2y-8)2=0,则x-y=______.