Question

1. Determinati numarul natural x stiind ca:
a) (2y-1)|35
b) (2y +3)|(3y +1)
Va rog mult.​

Answer 1

Explicație pas cu pas:

a)

(2y-1)|35 => (2y-1) ∈ {1, 5, 7, 35} |+1

2y ∈ {2, 6, 8, 36} |:2

y ∈ {1, 3, 4, 18}

b)

(2y +3) | (3y +1) <=> (2y +3) | 2×(3y +1)

(2y + 3) | (6y + 2) <=> (2y + 3) | [3×(2y + 3) - 7]

(2y + 3) | 3×(2y + 3) => (2y + 3) | 7

{2y + 3} ∈ {1, 7} |-3

2y ∈ {-2; 4} |:2

y ∈ {-1; 2}

y ∈ N => y = 2