25.不在3x+2yV6表示的平面区域内的点是()
A.(0,0)B.(1,1)
C.(0,2)D.(2,0)
[答案]D
[解析]将点的坐标代入不等式中检验可知,只有(2,0)点不满足3x+2yV6.
r/
yvx
26.不等式组+yw1,表示的区域为D,点P1(0,—2),点P2(0,0),则()
记>3
A.P1?
D,P2?
DB.P1?
D,P2€D
C.P1€D,P2?
DD.Pj€D,P?
€D
[答案]A
[解析]P1点不满足y》3.P2点不满足yvx.和y》3
•••选A.
27.已知点P(X0,y°)和点A(1,2)在直线1:
3x+2y—8=0的异侧,贝U()
A.3x0+2y0>0B.3xo+2yo<0
C.3x0+2y°<8D.3x0+2yo>8
[答案]D
[解析]•/3X1+2X1—8=—3<0,P与A在直线l异侧,•3x0+2y0—8>0.
28.图中阴影部分表示的区域对应的二元一次不等式组为(
x+y—1》0A.
lx—2y+2》0
x+y—1w0
B.U
x—2y+2w0
x+y—1>0x+y—K0
C.x—2y+2W0|x—2y+2>0
[答案]A
[解析]取原点0(0,0)检验满足x+y—1<0,故异侧点应为x+y—1>0,排除B、D•
O点满足x—2y+2》0,排除C•
•••选A•
17=®
%
H
)
29•不等式x2