5×(6.6-y)=12
8y-4=12-5y+9y
8y+12=8-8y-5y+10
y-12/y=?
微分方程y''-3y'+2y=5,y(0)=1,y'(0)=2求解过程
(1)y=2x-5 ,2x+3y=1 (2)x-y=3,x+y=5 (3)x+3y=11,3x+2y=12 用代入法解下
(1)y+3x+17=0 5y-2x+17=0 (2)x+y+z=12 x+2y+5z=22 x=4y (3)x+y+z
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+
解方程组 1(2x-3y=-1 y=2x-1 ) 2(2x+5y=12 2x+3y=6 )3(3x-2y=6 2x+3y
已知20(x+2y)=15(y+3Z)=12(z+5x),则x:y
若|5x+2y-12|+(3x-2y-6)平方=0,则x+2y=?
若X-2Y+6+(X+Y+12)²=0,求4X+ 5Y的值
化简求值:[(x+2y)2-(x+y)(3x-y)-5y2]÷2x,其中x=-2,y=12