Đáp án:
`| x + 2| = 7x + 4`
⇒\(\left[ \begin{array}{l}x + 2 = 7x + 4( x > -4/7)\\x + 2 = -7x - 4(x < -4/7)\end{array} \right.\)
⇒\(\left[ \begin{array}{l}-6x = 2\\8x = - 6\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=-1/3\\x=-3/4( mà -3/4 > - 4/7)\end{array} \right.\)
Vậy `S = {-1/3}`
`S={-1/3}`
Giải thích các bước giải:
`|x+2|=7x+4`
`|x+2|=x+2` nếu `x≥-2`
`-x-2` nếu `x<-2`
*Nếu `x≥-2` ta có:
`x+2=7x+4`
`⇔x-7x=4-2`
`⇔-6x=2`
`⇔x=-2/6`
`⇔x=-1/3(TM)`
*Nếu `x<-2` ta có:
`-x-2=7x+4`
`⇔-x-7x=4+2`
`⇔-8x=6`
`⇔x=-6/8`
`⇔x=-3/4(loại)`
Vậy `S={-1/3}`
Giải hộ mình với ạ, đề bài đây nha Rewrite these sentences by the words given
TURN INTO PASSIVE 17.You mustn’t touch this button while the experiment is in progress. 18.Did people make jeans two hundred years ago? 19.We don’t use this kind of cloth to make shirts. 20. Nothing will affect the result of the competition. => _________________________________ 21. No one has found the missing boy. => _________________________________ 23. Nobody protects the tower well. => _________________________________ 24. The storm didn’t kill anyone.
vẽ đậu mầm hoặc hoa quả hay kem ik NL:đói,nóng quá
ai lam em voi ak em dang can gap !!!
Turn into passive 4. Which book did you read last night? -> Which book ………………… 5. Who invented the telephone? ->By whom………………………… 6. Someone has stolen her motorbike. -> Her ……………………… 7. Someone had invented electric lights before I was born. -> Electric …………… 8. The students clean our class every day ->Our class ……………………… 9. My brother takes me to school every morning -> I ………………………… 10. built this castle in 1756. -> This …………………………… 11.They didn’t allow Tom to take these books home. 12.How many trees did they cut down to build that fence? 13.This well-known library attracts many people. 14.They didn’t look after the children properly. 15.Nobody swept this street last week. 16.She often takes her dog for a walk. Giúp mình vs nha, bài nhiều lười quá !
Vẽ chibi/ đậu mầm Nl: Tìm bạn chơi lâu dài:)) .
Giups với ạ mìn cảm ơn :)))))))))))))))))
write 1 question to ask a partner about his or her weekend. then take turns asking and aswering the westion with you
Tìm GTLN: A=-3x^2+x-7 B=-2x^2+y-5y+x+11 giúp mik với hứa 5 sao và CTLHN nếu đúng dễ hiểu và nhanh nha
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