(1)x-1=2x-1/4 (2)题目看不懂= =
两边同乘以4去分母得
4x-4=2x-1
移项得2x=3
x=1.5
(3)6+1/4(m-y)=2y 将y=3代入得
6+1/4(m-3)=6
移项得 1/4(m-3)=0
m-3=0
m=3
(4)4x+2m=3x+1 3x+2m=6x+1
移项得x=1-2m 移项得-3x=1-2m
x= -(1-2m)/3
因为它们的解相同,所以
1-2m= -(1-2m)/3
两边同时乘以3得3-6m= -(1-2m)
3-6m=2m-1
移项得-8m= -4
m=1/2
将m代入第2小题得
(1/2+ 2)^1999*(2*1/2-7/5)^2000
=(5/2)^1999*(2/5)^2000
=(5/2*2/5)^1999*2/5
=1*2/5
=2/5