Because of being ill, Lan had to stay at home

In spite of working very hard, she is poor

Because she was sick, she had to relax

Although I had breakfast this morning, I felt hungry

1.Because Lan was ill , she had to stay at home => Because of ...Lan's illness, she had to stay at home

2.Althought she works very hard , she is poor => In spite of ...working very hard, she is poor

3.Because of her sickness , she had to relax => Because ...she was sick, she had to relax

4. Despite having breakfast this morning , I felt hungry => Although I had breakfast this morning, I felt hungry

Lời giải:

$\frac{1}{2}(2^{n+4}+2^n)=17$

$2^{n+4}+2^n=17:\frac{1}{2}$

$2^n(2^4+1)=34$

$2^n.17=34$
$2^n=34:17=2=2^1$

$\Rightarrow n=1$

Lời giải:

$|x|\geq 6\Rightarrow x\geq 6$ hoặc $x\leq -6$

Với điều kiện như thế này thì không liệt kê được toàn bộ phần tử của $B$ bạn nhé. 

Đề yêu cầu gì vậy bạn?

`(x+1)/2 = (y+3)/4 = (z+5)/6 = (2x + 2)/4 = (4z + 20)/24`

Áp dụng t/chất dãy tỉ số bằng nhau: 

`=> (x+1)/2 = (y+3)/4 = (z+5)/6 = (2x + 2)/4 = (4z + 20)/24 = (2x + 2 + y + 3 -4z - 20)/(4 + 4 - 24) = (-1 + 2 + 3 - 20)/(-16) = (-16)/(-16) = 1`

`=> {((x+1)/2 = 1 -> x = 1 . 2 - 1 = 1),((y+3)/4 = 1 -> y = 1 .4 - 3 = 1),((z+5)/6 = 1-> z = 1.6-5=1)}`

Vậy ...

eh

Mình có lúp 5 thui

Sorry :(

1.    Write the second sentence so that it has the same meaning to the first

1, If you often go swimming, you will keep fit

è Swimming .....will keep you fit........................

         2, It's a good idea to do exersice regularly

è You ………should do exercise regularly…………….........

          3,  Tom’s gained 5 kilos since he quit smoking

è Tom’s put …on 6 kilos since he quit smoking…………………….

2.   Rewrite the sentence, using the given words

1,  You shouldn’t skip your breakfast

è ……It is unhealthy to ski[ your breakfast……………………………………….. (healthy)

          2,  Boys don’t have as much acne as girls

è ……Girls have more acne than boys………………………………………(than)

3,  Doing exersice every day is a good idea

è ………You should do exercise everyday……………………………………(should)

câu đó nghĩa là 

sở thích của tôi là gì

tôi đoán là học bài

\(a,\dfrac{5}{4}- \left(\dfrac{1}{2}\right)^2\)

\(=\dfrac{5}{4}-\dfrac{1}{4}\)

\(=1\)

\(b,\dfrac{2}{3}\cdot\dfrac{-3}{2}+\dfrac{-7}{2}\cdot\dfrac{2}{3}\)

\(=\dfrac{2}{3}\cdot\left(\dfrac{-3}{2}+\dfrac{-7}{2}\right)\)

\(=\dfrac{2}{3}\cdot-5\)

\(=-\dfrac{10}{3}\)

\(c,\left(\dfrac{1}{5}+\dfrac{4}{13}\right)+\left(\dfrac{-2}{5}+\dfrac{7}{13}\right)-\left(\dfrac{4}{5}-\dfrac{2}{13}\right)\)

\(=\dfrac{1}{5}+\dfrac{4}{13}-\dfrac{2}{5}+\dfrac{7}{13}-\dfrac{4}{5}+\dfrac{2}{13}\)

\(=\left(\dfrac{1}{5}-\dfrac{2}{5}-\dfrac{4}{5}\right)+\left(\dfrac{4}{13}+\dfrac{7}{13}+\dfrac{2}{13}\right)\)

\(=-1+1\)

`=0`

\(\dfrac{2^{32}.5^{24}}{5^{23}.2^{35}}=\dfrac{5^{24}}{5^{23}}.\dfrac{2^{32}}{2^{35}}=\dfrac{5^1}{2^3}=\dfrac{5}{8}\)

\(\dfrac{10^{15}.9^8.4^7}{20^{14}.3^{18}}=\dfrac{\left(2.5\right)^{15}.\left(3^2\right)^8.\left(2^2\right)^7}{\left(2^2.5\right)^{14}.3^{18}}=\dfrac{2^{15}.5^{15}.3^{16}.2^{14}}{2^{28}.5^{14}.3^{18}}=\dfrac{2^{29}.3^{16}.5^{15}}{2^{28}.3^{18}.5^{14}}=\dfrac{2.5}{3^2}=\dfrac{10}{9}\)

\(\dfrac{27^5.25^7}{125^5.9^8}=\dfrac{\left(3^3\right)^5.\left(5^2\right)^7}{\left(5^3\right)^5.\left(3^2\right)^8}=\dfrac{3^{15}.5^{14}}{5^{15}.3^{16}}=\dfrac{1}{5.3}=\dfrac{1}{15}\)

\(\dfrac{\left(-2\right)^{12}.9^4}{\left(-3\right)^9.16^2}=\dfrac{\left(-1.2\right)^{12}.\left(3^2\right)^4}{\left(-1.3\right)^9.\left(2^4\right)^2}=\dfrac{\left(-1\right)^{12}.2^{12}.3^8}{\left(-1\right)^9.3^9.2^8}=\dfrac{1.2^{12}.3^8}{\left(-1\right).2^8.3^9}=\dfrac{2^4}{\left(-1\right).3}=-\dfrac{8}{3}\)