由一个数的平方根互为相反数,
(1)|3x-y-1|=3x-y-1,
∴3x-y-1=2x+y-4,
x-2y=-5(1)
(2)|3x-y-1|=-(3x-y-1)=-3x+y+1
∴-3x+y+1=2x+y-4,
-5x=-5,得x=1,
代入(1)y=2
∴√(x+4y)=±3.
由一个数的平方根互为相反数,
(1)|3x-y-1|=3x-y-1,
∴3x-y-1=2x+y-4,
x-2y=-5(1)
(2)|3x-y-1|=-(3x-y-1)=-3x+y+1
∴-3x+y+1=2x+y-4,
-5x=-5,得x=1,
代入(1)y=2
∴√(x+4y)=±3.