a)
luam separat inecuatia 2x+5 ≤13 si o rezolvam
2x ≤13-5
2x ≤8
x ≤8:2
x ≤4
sa nu uiti ca N* inseamna multimea numerelor naturale fara 0
==> A={1,2,3,4}
b)
2(x+6)<12
2x+12<12
2x<12-12
2x<0
x<0 (nu se poate)
==> B=Ø (multimea vida)
c)
(2x+10x):2 ≤5x+4
12x:2 ≤5x+4
6x ≤5x+4
6x-5x ≤4
x ≤4
==> C={0,1,2,3,4}
d)
2(x+5)+3x<4(x+4)
2x+10+3x<4x+16
5x+10<4x+16
5x-4x<16-10
x<6
==> D={0,1,2,3,4,5}
e)
(2x+4x):3+3x ≤10
6x:3+3x ≤10
2x+3x ≤10
5x ≤10
x ≤10:5
x ≤2
==> E={1,2}
f)
3x+2x-15<10
5x-15<10
5x<10+15
5x<25
x<25:5
x<5
==> F={0,1,2,3,4}
sper ca ai inteles!
