Question

Determinati suma tuturor elementelor multimii A={x € Z | -2mai mic sau egal x+3 mai mic dau egal 5​

Answer 1

Răspuns:

Explicație pas cu pas:

A={x € Z | -2 ≤ x+3 ≤ 5​}

-2 ≤ x+3 ≤ 5

-2 - 3 ≤ x ≤ 5 - 3

-5 ≤ x ≤ 2

A = {-5, -4, -3, -2, -1, 0, 1, 2}

-5 - 4 - 3 - 2 - 1 + 0 + 1 + 2 = -12

Answer 2

Bună!

A={x∈Z | -2≤x+3≤5}

-2≤x+3≤5/-3 ⇔

⇔ -5≤x≤2

x∈{-5, -4, -3, -2, -1, 0, 1, 2} ⇒ A={-5, -4, -3, -2, -1, 0, 1, 2}

S=-5+(-4)+(-3)+(-2)+(-1)+0+1+2=

=-5-4-3-2-1+0+1+2=

=-9-3-2-1+1+2=

= -12

____________

∵ -1+1=0

∵ -2+2=0