Để x lớn nhất
\(\Leftrightarrow x-2>0\)
\(\Leftrightarrow x>2\)
Phá trị tuyệt đối , ta có :
1976 \(\le\)x - 2 < 1990
1976 + 2 \(\le\) x - 2 + 2 < 1990 + 2
1978 \(\le\)x < 1992
=> Maxx = 1991
=> Minx = 1978
\(1976\le\left|x-2\right|< 1990\)
\(\Rightarrow\left|x-2\right|\in\left\{1976;1977;1978;...;1988;1989\right\}\)
\(\Rightarrow x-2\in\left\{1976;-1976;1977;-1977;...;1989;-1989\right\}\)
\(\Rightarrow x\in\left\{1978;-1974;1979;-1975;...;1991;-1987\right\}\)