Question

Tìm x,y \(\in\) Z biết: \(\dfrac{-1}{3}\) < \(\dfrac{A}{36}\) <\(\dfrac{B}{18}\) <\(\dfrac{-1}{4}\) và A= x+1 ; B=2-y

Answer 1

\(-\dfrac{1}{3}< \dfrac{A}{36}< \dfrac{B}{18}< -\dfrac{1}{4}\)

<=>\(-\dfrac{12}{36}< \dfrac{A}{36}< \dfrac{2B}{36}< -\dfrac{9}{36}\)

<=> -12 < x + 1 < 2(2 - y) < -9

<=> -12 < x + 1 < 4 - 2y < -9

=> x + 1 = -11 => x = -12

4 - 2y = -10 => y = 7

Vậy (x; y) = (-12; 7)

Answer 2

<=>

<=> -12 < x + 1 < 2(2 - y) < -9

<=> -12 < x + 1 < 4 - 2y < -9

=> x + 1 = -11 => x = -12

4 - 2y = -10 => y = 7

Vậy (x; y) = (-12; 7)