8 .|2x – 9|=104 |2x-9| = 104 : 8 |2x+9| = 13 |2x| = 13 -9 |2x| = 4 : 2 => x ∈ { 2,-2} Vậy x ∈ { 2,-2} Trả lời
8 . |2x – 9| = 104<=>|2x – 9| = 104 : 8 = 13<=>|2x| = 13 – 9 = 4<=>|x| = 4 : 2 = 2<=>x \in {2;-2}Vậy x \in {2;-2} Trả lời
<=>|2x – 9| = 104 : 8 = 13
<=>|2x| = 13 – 9 = 4
<=>|x| = 4 : 2 = 2
<=>x \in {2;-2}
Vậy x \in {2;-2}