Question

9. Efectuează: a) {x|x€N şi 2​

Answer 1

1, 2 - prima si a doua multime

Re - reunit

Int - intersectat

a) 1. 2<x≤5 => x={3,4,5}

2. x<7=> x={0,1,2,3,4,5,6}

1 Re 2 ={0,1,2,3,4,5,6}

b) 1. x-1=4=>x=5

2. 3x+2=17=>3x=15=>x=5

1 Int 2 = {5}

c) 1. x=2n+1, n<3

n=2=> x=5

n=1=> x=3

n=0=> x=1

n=-1=> x=-1 care nu este natural

=> x={1,3,5}

2. x=3^p, p<2

p=1=> 3¹=3

p=0=> 3⁰=1

p=-1=> 3^(-1)=1/3 care nu este natural

x={1,3}

1 Re 2= {1,3}

d) 1. 2n=> x={0,2,4,6,8...}

2. 2n+1=> x={1,3,5,7,9...}

1 Re 2={0,1,2,3,4,5...}

e) 1 Int 2= Ø