Question

tìm x ϵ z , sao cho 

a) 6 chia hết cho x

b) 8 chia hết cho x + 1

Answer 1

a) 6 ⋮ x

⇒ x ∈ Ư(6) = {-6; -3; -2; -1; 1; 2; 3; 6}

b) 8 ⋮ (x + 1)

⇒ x + 1 ∈ Ư(8) ={-8; -4; -2; -1; 1; 2; 4; 8}

⇒ x ∈ {-9; -5; -3; -2; 0; 1; 3; 7}

Answer 2

Vì 6⋮ x

=> x ϵ { 1,2,3,6,-1,-2,-3,-6}

Vì 8 ⋮ x +1

=> x+1 ϵ { 1,2,4,8,-1,-2,-4,-8}

=> x ϵ {0,1,3,7,-2,-3,-5,-9}

=> x = -2