2 câu trả lời
(2x-1)2=49
(2x-1)2=(±7)2
→2x-1=±7
TH1:
2x-1=7
2x=8
x=8:2
x=4
TH2:
2x-1=-7
2x=-7+1
2x=-6
x=-6:2
x=-3
→ Vậy x ∈ {4;-3}
(2x-1)2=49
(2x-1)2=(±7)2
2x-1=±7
⇒ [2x−1=72x−1=−7
⇒ [2x=82x=−6
⇒ [x=4x=−3
Vậy S={4;-3}
(2x-1)2=49
(2x-1)2=(±7)2
→2x-1=±7
TH1:
2x-1=7
2x=8
x=8:2
x=4
TH2:
2x-1=-7
2x=-7+1
2x=-6
x=-6:2
x=-3
→ Vậy x ∈ {4;-3}
(2x-1)2=49
(2x-1)2=(±7)2
2x-1=±7
⇒ [2x−1=72x−1=−7
⇒ [2x=82x=−6
⇒ [x=4x=−3
Vậy S={4;-3}