Question

问1道数学题【100分】已知x、y满足 1/2|x-y|+|1-y|=0,求7x-3y的值.

Answer 1

|x-y|≥0,|1-y|≥0

0.5|x-y|+|1-y|=0

|x-y|=0,|1-y|=0

x-y=0,1-y=0

x=1,y=1

7x-3y=7*1-3*1=7-3=4