Question

5. Determinați elementele mulțimii A={x = N | x≤ 20, 3(10+x)}.​

Answer 1

X=0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20

3(10+x)

3(10+0)=30

3(10+1)=33

3(10+2)=36

3(10+3)=39

3(10+4)=42

3(10+5)=45

3(10+6)=48

3(10+7)=51

3(10+8)=54

3(10+9)=57

3(10+10)=60

3(10+11)=63

3(10+12)=66

3(10+13)=69

3(10+14)=72

3(10+15)=75

3(10+16)=78

3(10+17)=81

3(10+18)=84

3(10+19)=87

3(10+20)=90

A={30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,81,84,87,90}