Question

докажите тождество x-(1-(x-(1-x)))=3x-1

Answer 1

Тождество неверное

$x-(1-(x-(1-x)))=3x-1 \\x-(1-(x-1+x)=3x-1\\x-(1-2x+1)=3x-1\\x-(2-2x)=3x-1\\x-2+2x=3x-1\\3x-2=3x-1\\-2=-1\\x \in \O$