Question

help me pls dau coroana

Answer 1

Explicație pas cu pas:

d)

$|x + 3| < 5 \\ - 5 < x + 3 < 5 \\ - 8 < x < 5$

$x \in \mathbb{Z} = > A = \{ -7; -6; -5; - 4; - 3; - 2; - 1; 0; 1; 2; 3; 4 \}$

$|x| \leqslant 7 \\ - 7 \leqslant x \leqslant 7$

$x \in \mathbb{Z} = > B = \{ -7; -6; -5; - 4; - 3; - 2; - 1; 0; 1; 2; 3; 4; 5; 6; 7 \}$

e)

$4x + 11 > 67 \\ 4x > 67 - 11 \\ 4x > 56 \\ x > 56 \div 4 \\ = > x > 14$

$x \in \mathbb{N} = > A = \{15; 16; 17; 18... \}$

$7x - 5 \geqslant 72 \\ 7x \geqslant 72 + 5 \\ 7x \geqslant 77 \\ x \geqslant 77 \div 7 \\ x \geqslant 11$

$x \in \mathbb{N} = > B = \{11; 12; 13; 14; ... \}$

f)

$( {x}^{2} - 3) \: | \: 22 \\ x \in \mathbb{N} = >( {x}^{2} - 3) \in \{1;2;11;22\} \\ {x}^{2} \in \{4;5;14;25\} = > A = \{2;5\}$

$|x| \leqslant 5 \\ - 5 \leqslant x \leqslant 5$

$x \in \mathbb{Z} = > B = \{-5; - 4; - 3; - 2; - 1; 0; 1; 2; 3; 4; 5 \}$