Question

1. Numarul elementelor multimii A={x∈ ZΙ$- \sqrt{5}$≤x≤$\sqrt{10}$}
2.Determinati valorile intregi ale lui x pentru care $\frac{12}{3x+2}$ este numar intreg.
3.Calculati: ($\sqrt{3,24} -8. \sqrt{0,25}$ ) : (-0,01)

Answer 1

1.  √10 ≥ x ≥ - √5  ∪ x ∈ Z ⇒ x ∈ { - √4, - √1, 0 .√1,√4,√9)
x ∈{-2,-1,0,1,2,3]
2.  12/(3x + 2) ∈ Z ⇔  (3x + 2) ∈ D12
(3x + 2) ∈ {-12,-6,-4,-3,-2,-1,1,2,3,4,6,12}
3x ∈ {-14,-8,-6,-5,-4,-3,-1,0,1,2,4,10}
x ∈ { -2,-1,0,}
3.  (1,8 - 8·0,5) : (-0,01) = (1,8 - 4) : (-0,01) = (-2,2) : (-0,01) = 220