Question

1_Rezolvati in mulțimea nr întregii:
a)7(1-x)+21=14;
b)1-9x+5(2x-3)<-19

Answer 1

a) 7x-7+21=14
7x+14=14
7x=14-14
7x=0
x=0/7
x=0
b) 1-9x+10x-15<-19
-14+x<-19
x<-19+14
x<-5=>x aparține {..., -10, -9, -8, -7, -6}

Answer 2

a)7(1-x)+21=14
7-7x=14-21
7-7x=-7
7x=14
x=2

b)1-9x+5(2x-3)<-19
1-9x+10x-15<-19
x-14<-19
x<-5
x aparține {-∞..., -10, -9, -8, -7, -6}