Question

E={X E N | |2x+1|=7}
G={x E Z| |2x-5|=9}​

Answer 1

Explicație pas cu pas:

$|2x+1|=7$

$2x + 1 = - 7 \iff 2x = - 8 \\ x = - 4 \not \in \mathbb{N}$

$2x + 1 = 7 \iff 2x = 6 \\ x = 3 \in \mathbb{N}$

=> E = {3}

$|2x-5|=9$

$2x - 5 = - 9 \iff 2x = - 4 \\ x = - 2$

$2x - 5 = 9 \iff 2x = 14 \\ x = 7$

=> F = {-2; 7}