Question

Dacă A={x €Z |-7 <2x-1 <5} cardinalul mulțumii A este ...

Answer 1

$A=\{x\:\in\:\mathbb{Z}\:|-7<2x-1<5\}$

$- 7 < 2x - 1 < 5 \: | + 1$

$- 6 < 2x < 6 \: | \div 2$

$- 3 < x < 3$

$x \: \in \: \{ - 2, - 1,0,1,2 \}$

$A= \{ - 2, - 1,0,1,2 \}$

$= > cardA = 5$

Answer 2

.......................