Question

6. Determinați mulțimile: A = {xe N/(3x - 1)| 48};
B= {xe N/x= 4a2b , x 5 si a = b + 3}.​

Answer 1

Multimea A

(3x+1)l48=>(3x+1)€Divizori 48

D48= {1;2;3;4;6;8;12;16;24;48}

1. 3x+1=1

x=0

2.3x+1=2

x=1 / 3 Fals

3.3x+1=3

x=2/3 fals

4.3x+1=4

x=1

5.3x+1=6

x=5/3 fals

6.3x+1=8

x=7/3 fals

7.3x+1=12 fals

8.3x+1=16

x=5

9.3x+1=24 fals

10.3x+1=48 fals

A={0,1,5}

Multimea B

x e multiplu de 5 =>b=0 sau 5

1.b=0

a=3=>x=4320(daca era cu bara) sau daca era inmultire x=4*3*2*0=0

2.b=5

a=8=>x=4825(daca era cu bara)sau daca era inmultire x=4*8*5*2==32*10=320