ai giải hộ mình với ạ, thứ hai 8/11 hạn rồi:(
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\dfrac{9^{15}.8^{11}}{3^{29}.16^8}=\dfrac{\left(3^2\right)^{15}.\left(2^3\right)^{11}}{3^{29}.\left(2^4\right)^8}=\dfrac{3^{30}.2^{33}}{3^{29}.2^{32}}\)
Ta lấy vễ trên chia vế dưới
\(=3.2=6\)
\(\dfrac{2^{11}.9^3}{3^5.16^2}=\dfrac{2^{11}.\left(3^2\right)^3}{3^5.\left(2^4\right)^2}=\dfrac{2^{11}.3^6}{3^5.2^8}\)
Ta lấy vế trên chia vế dưới
\(=2^3.3=24\)
\(\dfrac{9^{15}.8^{11}}{3^{29}.16^8}=\dfrac{\left(3^2\right)^{15}.\left(2^3\right)^{11}}{3^{29}.\left(2^4\right)^8}=\dfrac{3^{30}.2^{33}}{3^{29}.3^{32}}=3.2=6\)
\(\dfrac{2^{11}.9^3}{3^5.16^2}=\dfrac{2^{11}.\left(3^2\right)^3}{3^5.\left(2^4\right)^2}=\dfrac{2^{11}.3^6}{3^5.2^8}=2^3.3=8.3=24\)
10. Câu này chứng minh BĐT BSC:
\(\sqrt{\left(a^2+b^2\right)\left(b^2+c^2\right)}\ge\sqrt{\left(ab+bc\right)^2}=b\left(a+c\right)\)
11.
Ta có: \(\dfrac{1}{1+a}+\dfrac{1}{1+b}-\dfrac{2}{1+\sqrt{ab}}\)
\(=\dfrac{\left(1+b\right)\left(1+\sqrt{ab}\right)}{\left(1+a\right)\left(1+b\right)\left(1+\sqrt{ab}\right)}+\dfrac{\left(1+a\right)\left(1+\sqrt{ab}\right)}{\left(1+a\right)\left(1+b\right)\left(1+\sqrt{ab}\right)}-\dfrac{2\left(1+a\right)\left(1+b\right)}{\left(1+a\right)\left(1+b\right)\left(1+\sqrt{ab}\right)}\)
\(=\dfrac{1+b+\sqrt{ab}+b\sqrt{ab}}{\left(1+a\right)\left(1+b\right)\left(1+\sqrt{ab}\right)}+\dfrac{1+a+\sqrt{ab}+a\sqrt{ab}}{\left(1+a\right)\left(1+b\right)\left(1+\sqrt{ab}\right)}-\dfrac{2+2a+2b+2ab}{\left(1+a\right)\left(1+b\right)\left(1+\sqrt{ab}\right)}\)
\(=\dfrac{-a-b+2\sqrt{ab}+a\sqrt{ab}+b\sqrt{ab}-2ab}{\left(1+a\right)\left(1+b\right)\left(1+\sqrt{ab}\right)}\)
\(=\dfrac{\left(\sqrt{a}-\sqrt{b}\right)^2\left(\sqrt{ab}-1\right)}{\left(1+a\right)\left(1+b\right)\left(1+\sqrt{ab}\right)}\ge0\forall x,y\ge1\)
Đẳng thức xảy ra khi \(a=b=1\)
Ai giúp mình với! Đang cần gấp hạn nộp là mai rồi các bạn giải thì kèm theo giải thích hộ mifng với cô bắt giải thích!!!!
Exercise 1: Find the word which has a different sound in the part underlined
1. A. prefer | B. better | C. teacher | D. worker |
2. A. future | B. return | C. picture | D. culture |
3. A. pottery | B. flower | C. silent | D. service |
4. A. girl | B. expert | C. open | D. burn |
5. A. worst | B. learn | C. control | D. dessert |
Exercise 2: Put the verb in brackets in the correct verb form
1. I (see)___will see___ a film this Sunday evening. (you/ go) __Will you go___ with me?
2. They (give)___will give__a party next week.
3. The members of the stamp collectors’ club (meet)__will meet____ at the library next Friday.
4. (you/ be)____You will be____ free next Sunday.
5. We (live)___live___ near Nam’s house, but we (not see)___don't see____him very often.
6. Don’t worry. I (go)__will go____fishing with you next Saturday morning.
Trang Trần
Exercise 1: Find the word which has a different sound in the part underlined
1. A. prefer /3:/ | B. better /ər/ | C. teacher /ər/ | D. worker /ər/ |
2. A. future /tʃər/ | B. return /tɜːn/ | C. picture /tʃər/ | D. culture /tʃər/ |
3. A. pottery /ə/ | B. flower /ə/ | C. silent /ə/ | D. service /ɜː/ |
4. A. girl /ɜː/ | B. expert /ɜː/ | C. open /ə/ | D. burn /ɜː/ |
5. A. worst /ɜː/ | B. learn /ɜː/ | C. control /əʊ/ | D. dessert /ɜː/ |
Exercise 2: Put the verb in brackets in the correct verb form
1. I (see)___will see___ a film this Sunday evening (Thì tương lai đơn). (you/ go) __Will you go___ with me?
2. They (give)___will give__a party next week (Thì tương lai đơn).
3. The members of the stamp collectors’ club (meet)__will meet____ at the library next Friday(Thì tương lai đơn).
4. (you/ be)____You will be____ free next Sunday (Thì tương lai đơn).
5. We (live)___live___ near Nam’s house, but we (not see)___don't see____him very often (Thì hiện tại đơn).
6. Don’t worry. I (go)__will go____fishing with you next Saturday morning (Thì tương lai đơn).
thời gian 2 xe gặp nhau là:
27:(54-36)=1,5 giờ=1 giờ 30 phút
đáp số: 1 giờ 30 phút
`2x+5y=11(1)`
`2x-3y=0(2)`
Lấy (1) trừ (2)
`=>8y=11`
`<=>y=11/8`
`<=>x=(3y)/2=33/16`
a) Ta có: \(\left\{{}\begin{matrix}2x+5y=11\\2x-3y=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}8y=11\\2x-3y=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=\dfrac{11}{8}\\2x=3y=3\cdot\dfrac{11}{8}=\dfrac{33}{8}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{33}{16}\\y=\dfrac{11}{8}\end{matrix}\right.\)
Vậy: Hệ phương trình có nghiệm duy nhất là \(\left\{{}\begin{matrix}x=\dfrac{33}{16}\\y=\dfrac{11}{8}\end{matrix}\right.\)
b) Ta có: \(\left\{{}\begin{matrix}4x+3y=6\\2x+y=4\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}4x+3y=6\\4x+2y=8\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=-2\\2x+y=4\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}2x-2=4\\y=-2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2x=6\\y=-2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=3\\y=-2\end{matrix}\right.\)
Vậy: Hệ phương trình có nghiệm duy nhất là (x,y)=(3;-2)
\(=\dfrac{3^{15}\cdot2^{22}+2^8\cdot2^{16}\cdot3^{16}}{2\cdot3^{18}\cdot2^{21}-7\cdot3^{15}\cdot2^{23}}\)
\(=\dfrac{3^{15}\cdot2^{22}\left(1+2^2\cdot3\right)}{3^{15}\cdot2^{22}\left(3^3-7\cdot2\right)}=\dfrac{1+4\cdot3}{27-14}=1\)
em muốn giải lắm nhưng lại là lớp 5