3)Tìm x a) x.(11 phần 5)mũ27 =(11 phần 5)mũ29 b) (2x-1)mũ2 = 1 phần 4 06/07/2021 Bởi Valerie 3)Tìm x a) x.(11 phần 5)mũ27 =(11 phần 5)mũ29 b) (2x-1)mũ2 = 1 phần 4
`a) x.(11/5)^{27} = (11/5)^{29}` `<=> x = (11/5)^{29} : (11/5)^{27}` `<=> x = (11/5)^2` `<=> x = 121/25` `b) (2x – 1)^2 = 1/4` `<=> |2x – 1| = 1/2` `<=>` \(\left[ \begin{array}{l}2x – 1 = \dfrac{1}{2}\\2x – 1 = -\dfrac{1}{2}\end{array} \right.\) `<=>` \(\left[ \begin{array}{l}x = \dfrac{3}{4}\\x = \dfrac{1}{4}\end{array} \right.\) Bình luận
`a,x·(11/5)^27=(11/5)^29` `→x=(11/5)^29÷(11/5)^27` `→x=(11/5)^2=121/25` `b,(2x-1)^2=1/4` `→|2x-1|=1/2` `→2x-1=1/2` hoặc `2x-1=-1/2` `→2x=3/2` hoặc `2x=1/2` `→x=3/4` hoặc `x=1/4` Bình luận
`a) x.(11/5)^{27} = (11/5)^{29}`
`<=> x = (11/5)^{29} : (11/5)^{27}`
`<=> x = (11/5)^2`
`<=> x = 121/25`
`b) (2x – 1)^2 = 1/4`
`<=> |2x – 1| = 1/2`
`<=>` \(\left[ \begin{array}{l}2x – 1 = \dfrac{1}{2}\\2x – 1 = -\dfrac{1}{2}\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x = \dfrac{3}{4}\\x = \dfrac{1}{4}\end{array} \right.\)
`a,x·(11/5)^27=(11/5)^29`
`→x=(11/5)^29÷(11/5)^27`
`→x=(11/5)^2=121/25`
`b,(2x-1)^2=1/4`
`→|2x-1|=1/2`
`→2x-1=1/2` hoặc `2x-1=-1/2`
`→2x=3/2` hoặc `2x=1/2`
`→x=3/4` hoặc `x=1/4`