若|x+y-5|+(x-y-9)的平方=0,则x,y的值分别为( )A.-2,7B.7,-2C.-7,2D.2,-7

来源:学生作业帮助网 编辑:作业帮 时间:2024/10/19 19:03:02
若|x+y-5|+(x-y-9)的平方=0,则x,y的值分别为( )A.-2,7B.7,-2C.-7,2D.2,-7
x){ѽBR״F[BRR;7?@i JHÞmO;V?ٱ{:tt̝uttu\ttm)0b6 ̄fB/p ~dR0* V e?i0ӨBEg-ĚJ _6t:$A=g8Ej)WwX@t*A` 6C:((E^SS64#9i{XrȚ`@w)((

若|x+y-5|+(x-y-9)的平方=0,则x,y的值分别为( )A.-2,7B.7,-2C.-7,2D.2,-7
若|x+y-5|+(x-y-9)的平方=0,则x,y的值分别为( )
A.-2,7
B.7,-2
C.-7,2
D.2,-7

若|x+y-5|+(x-y-9)的平方=0,则x,y的值分别为( )A.-2,7B.7,-2C.-7,2D.2,-7
|x+y-5|+(x-y-9)的平方=0
所以
x+y-5=0
x-y-9=0
相加
2x-14=0
所以x=7
y=x-9=-2
选B

B,x+y-5=0,x-y-9=0;联立解得x=7,y=-2

选B
|x+y-5|≥0
(x-y-9)²≥0
所以只能是
|x+y-5|=(x-y-9)²=0
x+y-5=0
x-y-9=0
x=7 y=-2