12.9
a
x-5+1<5 V x-5+1>-5
x<9 V X>-1
X∈(-1;9)
b
x+6+1>4 V x+6+1<-4
x>-3 V x<-11
x∈ (-∞;-11)V(-3;∞)
c
4-x-2>3 V 4-x-2<-3
X<-1 V X>5
X∈(-∞;-1) V (5;∞)
d
2-x+9>7/3 V 2-x+9<-7/3
x<8²/₃ V X> 13⅓
X∈ (-∞; 8²/₃ ) V (13⅓;∞)
12,7
a
x-7=9 V x-7=-9
x=16 V x=-2
b
x+9=1 V x+9=-1
x=-8 V x=-10
c
x-8=1 V x-8=-1
x=9 V x=7
d
x+7=0
x=-7
