问题
选择题
已知-1<y<3,化简|y+1|+|y-3|=( )
A.4
B.-4
C.2y-2
D.-2
答案
∵-1<y<3,
∴|y+1|=y+1,
|y-3|≤0,|y-3|=-y+3,
∴|y+1|+|y-3|=y+1-y+3=4.
故选A.
已知-1<y<3,化简|y+1|+|y-3|=( )
A.4
B.-4
C.2y-2
D.-2
∵-1<y<3,
∴|y+1|=y+1,
|y-3|≤0,|y-3|=-y+3,
∴|y+1|+|y-3|=y+1-y+3=4.
故选A.