已知| x-3 | + | y-1/2 |=0,求式子3x+2y的值

问题描述:

已知| x-3 | + | y-1/2 |=0,求式子3x+2y的值

| x-3 | + | y-1/2 |=0
x-3=0,y-1/2=0
x=3,y=1/2
3x+2y=3*3+2-1/2=9+1=10

因为绝对值必须不少于0
所以当| x-3 | + | y-1/2 |=0时,必须有| x-3 |=0和| y-1/2 |=0
由此解得x=3和y=1/2
3x+2y
=10

因为|x-3|>=0, |y-1/2|>=0
又| x-3 | + | y-1/2 |=0
所以 x-3=0, y-1/2=0
x=3 y=1/2
3x+2y=10

x-3=0
x=3
y-1/2=0
y=1/2
代入得
3x+2y=9+1=10
答案是10

|x-3|+|y-1/2|=0
因为|x-3|≥0,|y-1/2|≥0
所以|x-3|=0,|y-1/2|=0
x-3=0,y-1/2=0
x=3,y=1/2
3x+2y=3×3+2×(1/2)=9+1=10