Question

ex : 26
si 27
Va rog!!!
Dau coroana....!!!

Answer 1

26) b) (4x + 1) | 75
75 = 1 x 3 x 25 = 1 x 3 x 5 x 5
4x + 1 = 1, x = 0
4x + 1 = 3, 4x = 2, x = 1/2 ∉ N
4x + 1 = 15, 4x = 14, x = 7/2 ∉ N
4x + 1 = 5, 4x = 4, x = 1
4x + 1 = 25, 4x = 24, x = 6
4x + 1 = 75, 4x = 74, x = 37/2 ∉ N
A = {0, 1, 6}

e) 81 = 1 x 9 x 9 = 1 x 3 x 3 x 3 x 3
4x + 1 = 1, x = 0
4x + 1 = 3, 4x = 2, x = 1/2∉N
4x + 1 = 9, 4x = 8, x = 2
4x + 1 = 27, 4x = 26, x = 13/2∉N
4x + 1 = 81, 4x = 80, x = 20
A = {0, 2, 20}

27)
a) D28 = {1, 2, 4, 7, 14, 28}
D49 = {1, 7, 49}

D28 ∪ D49 = {1, 2, 4, 7, 14, 28, 49}
D28 ∩ D49 = {1, 7}
D28 - D49 = {2, 14, 28}
D49 - D28 = {49}