Đáp án+Giải thích các bước giải:
`P=\frac{\sqrt{x}}{\sqrt{x}+3}(x≥0)`
`P=\frac{1}{2}`
`⇔\frac{\sqrt{x}}{\sqrt{x}+3}=frac{1}{2}`
`⇔2\sqrt{x}=\sqrt{x}+3`
`⇔2\sqrt{x}-\sqrt{x}=3`
`⇔\sqrt{x}=3`
`⇔x=9(tm)`
Vậy `x=9` thì `P=\frac{1}{2}`
Đề không rõ nên mk chia 2 trường hợp
TH1:
$P$=$\dfrac{1}{2}$ ⇔ $2\sqrt[]{x}$ = $\sqrt[]{x}+3$ ($x$\geq$ $0$)
⇔ $2\sqrt[]{x}$-$\sqrt[]{x}$=$3$
⇔ $\sqrt[]{x}$=$3$
⇔ $(\sqrt[]{x})^2$=$9$
⇔ $x=9$
TH2:
$P$=$\dfrac{1}{2}$ ⇔ $2\sqrt[]{x}$ = $\sqrt[]{x+3}$ ($x$\geq$ $0$)
⇔ $(2\sqrt[]{x})^2$ = $(\sqrt[]{x+3})^2$
⇔ $4x$=$x+3$
⇔ $4x-x$=$3$
⇔ $3x=3$
⇔ $x=1$
21. Sam said, “Christine plays the guitar very well.” A. Sam said that Christine played the guitar very well. B. Sam said that Christine is playing the guitar very well. C. Sam said that Christine had played the guitar very well. D. Sam said that Christine plays the guitar very well. 22. Yoko said, “I have to finish the rehearsal before lunchtime.” A. Yoko said that I have to finish the rehearsal before lunchtime. B. Yoko said that she has got to finish the rehearsal before lunchtime. C. Yoko said that she had to finish the rehearsal before lunchtime. D. Yoko said that she has had to leave the class before lunchtime. 23. “John left here an hour ago,” said Jane. A. Jane told me that John had left there an hour before. B. Jane said John left here an hour ago. C. Jane told John to have left there an hour before. D. Jane told me that John to leave there an hour before. 24. “I will pay back the money, Gloria,” said Ivan. A. Ivan apologised to Gloria for borrowing her money. B. Ivan offered to pay Gloria the money back. C. Ivan promised to pay back Gloria’s money. D. Ivan suggested paying back the money to Gloria. 25. “I can’t explain this rule to you,” said my classmate to me. A. My classmate told me he / she can’t explain that rule to me. B. My classmate told me he / she couldn’t explain that rule to me. C. My classmate told me he / she can’t explain that rule to you. D. My classmate said me he / she couldn’t explain that rule to me.
Giúp mình vs ạ. Cảm ơn nhìu và hứa cho 5 sao ạ. 1. We own 100 acres of farmland while our neighbours own only 50. (Half) ->Our neighbours..............as we do. 2. At least 1000 machinists went on strike in support of the miners. (Came) -> No fewer....... With the miners. 3. He was promoted to captain because he was a great leader. (Virtue) He was promoted........qualities. 4. He was nearly killed in the accident. (Teeth) -> Only...... Escape death in the accident.
mọi người giuos mình với ạ mình cần gấp lắm
Tính các cạnh của tam giác ABC biết AB=10cm, BC=12cm, góc B=65 độ Giúp e vs ạ. E đang cần gấp
phân tích đa thức thành nhân tử nha cảm ơn
Làm ơnnn giúppppo với ạ chi tiết càng đội ơn ạ
Tóm tắt nàng Công chúa và hạt đậu
tui đang cần gấp giúp nhanh nha
Sự ra đời của các chính đảng công nhân ở các nước có ý nghĩa gì?
Chọn + giải thích giúp mình 3 câu
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