a)x+2×(3x-1)< sau egal cu 12
x=1
1+2×(3×1-1)=1+2×(3-1)=1+2×2=1+4=5
x=2
2+2×(3×2-1)=2+2×(6-1)=2+2×5=2+10=12
b)5(x+1)+2(×+1)<sau efal cu 42