1)[9+(-125]:(-4)-26
-116:(-4)-26
29-26=3
2)-3 < sau = |x+2| < sau = 3
-3 < sau = x+2 < sau = 3|-2
-5 < sau = x < sau = 1 =>A={-5;-4;-3;-2;-1;0;1}
3)1a7b:45=1a7b:9
1a7b:5 (9,5)=1
1a7b:5 <=> b apartine {0,5}
a)b=0=>1a70:9 <=> (1+a+7+0):9 ,<=>8+a:9=>a=1=>1170
b)b=5=>1a75:9 <=>(1+a+7+5):9 <=> 13+a:9=>a=5 =>1575
=>1a7b={1170;1575}