(2×X-1)²=5⁴:25 Làm hộ mình với ạ Question (2×X-1)²=5⁴:25 Làm hộ mình với ạ in progress 0 Môn Toán Nem 4 years 2020-10-15T13:42:22+00:00 2020-10-15T13:42:22+00:00 2 Answers 136 views 0
Answers ( )
`(2x – 1)² = 5⁴ : 25`
Trường hợp 1:
`(2x – 1)² = 5⁴ : 5 ²`
`(2x – 1)² = 5²`
`→ (2x – 1) = 5`
`→ 2x = 6`
`→ x = 3`
Trường hợp 2:
`(2x – 1)² = – 5²` `(`Vì `- 5² = 5²)`
`→ (2x – 1) = – 5`
`→ 2x = – 4`
`→ x = – 4 : 2`
`→ x = – 2`
Vậy, `x ∈ {3; – 2}`
– Answered by Meett1605
$(2×x-1)^{2}$ `=`$5^{4}$ : `25`
`⇒` $(2×x-1)^{2}$ `=` $5^{4}$ : $5^{2}$
`⇒` $(2×x-1)^{2}$ `=` $5^{2}$
`⇒` `2×x-1` `=` `±5`
Trường hợp `1` :
`2×x-1` `=` `5`
`⇒` `2×x` `=` `5+1`
`⇒` `2×x` `=` `6`
`⇒` `x` `=` `6:2`
`⇒` `x` `=` `3`
Trường hợp `2` :
`2×x-1` `=` `-5`
`⇒` `2×x` `=` `-5+1`
`⇒` `2×x` `=` `-4`
`⇒` `x` `=` `-4:2`
`⇒` `x` `=` `-2`
Vậy `x` `∈` `{ `3` ; `-2` }`