Question

fie multimile A={x|x E N si 2x mai mic sau egal cu 7} si B={x|x E N si x + 2<5}

Answer 1

➡A = { x | x € N si 2x <= 7 }

2x <= 7 ; x € N => x = { 0, 1, 2, 3, ... }

⛅ x = 0 ✨

2 x 0 <= 7

0<= 7 " A "

⛅ x = 1 ✨

1 x 2 <= 7

2 <= 7 " A"

⛅ x = 2 ✨

2 x 2 <= 7

4 <= 7 " A "

⛅ x = 3 ✨

3 x 2 <= 7

6 <= 7 "A"

⛅ x = 4 ✨

4 x 2 < = 7

8 <= 7 " F "

=> x € { 0, 1, 2, 3} ☑

✏B = { x | x €N si x + 2 < 5 }

x + 2 < 5

x < 5 - 2

x < 3

x € { 0, 1, 2 }

⚡Verificare:

• 0 + 2 < 5 => 2 < 5 " A"
• 1 + 2 < 5 => 3 < 5 "A"
• 2 + 2 < 5 => 4 < 5 " A"
• 3 + 2 < 5 => 5 < 5 "F"

=> x € { 0, 1, 2 } ✔