giải ik mn 

x\(\in\varnothing\)

                           2x+1 chia hết cho 3x+2

suy ra                 3(2x+1) chia hết cho 3x+2

suy ra                  6x+3: 3x+2

suy ra                 6x+4-1 chia hết cho 3x+2

suy ra                  -1 : 3z+2

suy ra                   5x+2 thuộc uc(-1)

\(\frac{3}{4}\)của 60 là :

\(\frac{3}{4}\times60=45\)

:)))))))))))))))))

3/4.60=45 nha

\(\frac{3}{4}x60=45\)

kb nha

k nha

Trò chuyện vs mk nhé bn

nếu muốn hết buồn bạn hãy xem hài cho hết buồn

Bài 3:

a. \(R=p\dfrac{l}{S}=1,1.10^{-6}\dfrac{30}{0,2.10^{-6}}=165\Omega\)

b. \(Q=UIt=220\left(\dfrac{220}{165}\right).15.60=254000\left(J\right)\)

Bài 2:

a. \(R=\dfrac{U^2}{P}=\dfrac{220^2}{1000}=48,4\Omega\)

b. \(Q=UIt=220\left(\dfrac{220}{48,4}\right).4.3600=14400000\left(J\right)\)

c. \(Q'=Q.40=14400000.40=576000000\left(J\right)=120000\)kWh

\(\Rightarrow T=Q'.2100=120000.2100=252000000\left(dong\right)\)

Bài 1:

a. \(Q=UIt=220.2,5.1=550\left(J\right)\)

b. \(\left\{{}\begin{matrix}Q_{thu}=mc\left(t-t_1\right)=2.4200\left(100-20\right)=672000\left(J\right)\\Q_{toa}=UIt=220.2,5.15.60=495000\left(J\right)\end{matrix}\right.\)

\(\Rightarrow H=\dfrac{Q_{toa}}{Q_{thu}}100\%=\dfrac{495000}{672000}100\%\approx73,6\%\)

Ta có:

${}^{}=10000{}^{}+{}^{}cd+{}^{}$

$=9999{}^{}+99{}^{}+{}^{}+{}^{}+{}^{}$

$=\left(9999{}^{}+99{}^{}\right)+\left({}^{}+{}^{}+{}^{}\right)$

$=\left(\mathrm{11.909.}{}^{}+11.9{}^{}\right)+\left({}^{}+{}^{}+{}^{}\right)$

$=11\left(\mathrm{909.9.}{}^{}.{}^{}\right)+\left({}^{}+{}^{}+{}^{}\right)$

Mà: ⎧⎪ ⎪⎨⎪ ⎪⎩11(909.9.¯¯¯¯¯ab.¯¯¯¯¯cd)⋮11(¯¯¯¯¯ab+¯¯¯¯¯cd+¯¯¯¯¯eg)⋮11{11(909.9.ab¯.cd¯)⋮11(ab¯+cd¯+eg¯)⋮11

⇒11(909.9.¯¯¯¯¯ab.¯¯¯¯¯cd)+(¯¯¯¯¯ab+¯¯¯¯¯cd+¯¯¯¯¯eg)⋮11⇒11(909.9.ab¯.cd¯)+(ab¯+cd¯+eg¯)⋮11

Hay ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯abcdeg⋮11abcdeg¯⋮11 (Đpcm)

thanks bn nha

mà hơi dài 1 chút hihi

toán NC là toán j ??????????

240 000; 420 000; 402 000; 204 000; 400 200; 400 020; 200 040; 200 400

2 she had got the price of the contest, she would be happy now

3 I had gone to the concert last night ,I would be tired

4 John had finished all his homework, he could see a movie now

5 we had listened to my mother, we wouldn't be in trouble right now

Ex5

1 you arrive at the offcie earlier than I do, please turn on the air-conditioner

2 Were it not snowy, the children would go to school

3 he not died so young, he would be a famous musician

4 Were I you, I would take care of my car

5 not very bad-tempered, his wife would give him soon are marrage

6 Had she not got married at such an early age, he would be at university

C D D D D 

I do

what

do

practise
in june

1 d

2d

3d

4d

5d

1 I do

2what

3do

4practise

5in june