Question

aflati x apartine multimii numerelor naturale din egalitatea:
a)x+13,6<17,4
b)Xx3,2<12,7
c)18,4-x<12,7
d)x-7,9<10,3
e)Xx7,8>12,2

Answer 1

a) x + 13.6 < 17.4
    x < 17.4 - 13.6
    x < 3.8
    x ∈ {3,2,1,0}

b) 3,2x < 12.7
    x < 12.7 : 3.2
    x < 3.9
    x ∈ {3,2,1,0}
c) 18.4 - x < 12.7
    -x < 12.7 - 18.4
    -x < -5.7 / · - 1
     x > 5.7
     x ∈ {6,7,8......(infinit)}
d) x - 7.9 < 10.3
    x < 10.3 + 7.9
    x < 18.2
    x ∈ {18,17,16,15....3,2,1,0}
e) 7.8x > 12.2
    x > 12.2 : 7.8
    x > 1.56
    x ∈ {2,3,4,5....(infinit)}