Question

Va rog! Poză mai sus! Dau coroană! Repede! Tot testul 5!​

Answer 1

1. a) A

b) A

2. [2,3] = 2×3 = 6

M6={0,6,12,18,24,30...}

S={0,6,12,18,24,30}

3. 12×n>100

n>8,(3) => n=9 => 12×9=108

12×n<1000

n<83,(3) => n=83 => 12×83=996

4. 2520=2³×3²×5×7

5. 10 | a => D10 | a => 1,2,5 | a

6. 23x divizibil cu 4

xyz (cu bara) div 4 => yz(cu bara)÷4=n∈N

=> 3x (cu bara) ÷ 4 = n ∈ N

3x÷4=c rest 0 => 4c=3x <=> 4c=30+x => c=(30+x)/4

c ∈ N => (30+x)/4 ∈ N

x=1 => 31/4 nu apartine

x=2 => 32/4=8

x=3 => 33/4 nu apartine

x=4 => 34/4 nu apartine

x=5 => 35/5 nu apartine

x=6 => 36/4=9

x=7 => 37/9 nu apartine

x=8 => 38/9 nu apartine

x=9 => 39/9 nu apartine

S={2,6}