( 2^3.3^2 - 5^4:5^2 ) + 2017^0
Đề ôn thi giúp mik nhé!!Mơn trc.
30 + 2.x = 4 mũ 2017 : 4 mũ 2015
Giúp mik nhé !! Đề ôn thi mik cần gắp mơn các bn.
\(30+2x=4^{2017}:4^{2015}\)
\(\Rightarrow30+2x=4^2=16\)
\(\Rightarrow2x=16-30=-14\)
\(\Rightarrow x=-14:2=-7\)
30 + 2x = 42017 : 42015
30 + 2x = 42
30 + 2x = 16
2x = 16 - 30
2x = -14
x = - 7
30+2.x =\(4^{2017}:4^{2015}\)
\(\Rightarrow30+2x=4^{2017-2015}\)\(\Rightarrow30+2x=16\)
\(\Rightarrow2x=-14\Rightarrow x=-7\)
Vậy x=
Tìm x:
3(x-2)+4(5-x)=8
GIÚP MIK NHÉ! MƠN NHÌU!!!!
3(x-2)+4(5-x)=8
=> 3x - 6 + 20 - 4x =8
=>-x=-6 => x=6
x^3-3x^+x+5=0 (giải pt)
lm hộ mik nhé mơn trc ạ
x^3 - 3x^2 + x + 5 = 0
=> x^3 + x^2 - 4x^2 - 4x + 5x + 5 = 0
=> x^2(x + 1) - 4x(x + 1) + 5(x + 1) = 0
=> (x^2 - 4x + 5)(x + 1) = 0
x^2 - 4x + 5 > 0
=> x + 1 = 0
=> x = -1
Uyên ơi! Chúng ta không dùng dấu "=> " mà dùng " <=> "
Nếu em dùng " => " thì phải có bước cuối cùng là thử x = -1 vào phương trình xem có thỏa mãn không nhé!
Thử x = -1 vào phương trình ta có: ( -1) ^3 - 3(-1)^2 + (-1) +5 = 0 đúng
Vậy x = -1 là nghiệm.
33/17 nhân 34/3 nhân 2/5 bằng bao nhiêu?
giúp mình nhé mình đang phải ôn thi
\(=\dfrac{33}{17}\cdot\dfrac{34}{3}\cdot\dfrac{2}{5}=\dfrac{2\cdot11\cdot2}{5}=\dfrac{44}{5}\)
\(\dfrac{33}{17}\times\dfrac{34}{3}\times\dfrac{2}{5}=11\times2\times\dfrac{2}{5}=\dfrac{44}{5}\)
Giups mik vs mik cảm mơn trc ah~~
1.ba can (fix)..............the lights.
2. you(be)...........a famous author one day.
3. you(have)......lots or friends soon.
4.we..........(not go) camping next week.we............(visit) the museum.
5. miss Thanh is ajournalist.she (not write)......for Lao Dong Newspaper.she(write)....for Nhan Dan Newspaper.
6. i'd like...............(join) your club.
7.why....you(make)..........so much noise in your room,Lan?
8. we(rehearse).......a play for the school anniversary celebrations.
9. my sister (practice)......the violin in the club twice a week.
10. they(givE)........a farewell party next week.
11.what..........your father usually (do)......in the evening?
12. he usually(watch).......TV, but sometimes he (read).......books.
13. we(not go)........to the cinema very often.
14.i (see)......a movie next saturday. .................you(go).................with me?
15. would you like(listen ) ........to music?
16. Mr. Thanh ...........(be) a doctor. He ..............(work)in a hospital in the city center. every day,he.........(catch)the bus to word.
Tranformation:
Nam's favorite sport is badminton.
=> Nam _________________ best.
Giúp mik nhé - Mơn mí bn nhìu~~~
Sắp đến kì thì HK2 òi, mí bn ôn bài thi thật tốt nhé!!!
Thanks mấy bn 1 lần nx.Hjhj
Tranformation:
Nam's favorite sport is badminton.
=> Nam s playing badminton best.
\(\sqrt{x^2-2x+4}+\sqrt{x^2+5}=9-2x\)
Làm giúp mik bài này với ạ mik cảm mơn
\(\sqrt{x^2-2x+4}+\sqrt{x^2+5}=9-2x\left(đk:x\le\dfrac{9}{2}\right)\)
\(\Leftrightarrow x^2-2x+4+x^2+5+2\sqrt{\left(x^2-2x+4\right)\left(x^2+5\right)}=81-36x+4x^2\)
\(\Leftrightarrow2\sqrt{\left(x^2-2x+4\right)\left(x^2+5\right)}=2x^2-34x+72\)
\(\Leftrightarrow4\left(x^2-2x+4\right)\left(x^2+5\right)=4x^4+1156x^2+5184-136x^3+288x^2-4896x\)
\(\Leftrightarrow4x^4-8x^3+36x^2-40x+80=4x^4-136x^3+1444x^2-4896x+5184\)
\(\Leftrightarrow128x^3-1408x^2+4856x-5104=0\)
\(\Leftrightarrow128x^2\left(x-2\right)-1152x\left(x-2\right)+2552\left(x-2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(128x^2-1152x+2552\right)=0\)
\(\Leftrightarrow x=2\left(tm\right)\)(do \(128x^2-1152x+2552>0\))
chứng minh 1/4 <1/5 +2/5^2 + 3/5^3 + 4/5^4 + ... + 2017/5^2017 < 1/3
giúp mik nha
hôm nay mik xin mở một cuộc thi toán dành cho các bn lớp 4 để các bn ôn lại kiến thức trong hề này nhé
phần 1 : đề : tính :
4/5 + 5/6 : 3/2 =.......................................................
3/5:4/6 - 3/1 = ...................................................................
4/6 : 5/4 + 3/2 = ..................................................................
chúc các bn thành công
p/s : chỉ dành cho 5 người đầu tiên trả lời rùi mik chấm thui nha
4/5 + 5/6 : 3/2
= 4/5 + 5/9
= 61/45
3/5 : 4/6 - 3/1
= 9/10 - .3
= -21/10
4/6 : 5/4 + 3/2
= 8/15 + 3/2
= 61/30
\(\frac{4}{5}\)+ \(\frac{5}{6}\): \(\frac{3}{2}\)= \(\frac{61}{45}\)
\(\frac{3}{5}\): \(\frac{4}{6}\)- \(\frac{3}{1}\)= - \(\frac{21}{10}\)= -2,1
\(\frac{4}{6}\): \(\frac{5}{4}\)+ \(\frac{3}{2}\)= \(\frac{61}{30}\)
4/5+5/6:3/2
=4/5+5/6.3/2
=4/5+5/4
=16/20+25/20
=41/20
3/5:4/6-3
=3/5.6/4-3
=9/10-3
=-21/10
4/6:5/4+3/2
=4/6.4/5+3/2
=16/30+45/30
=61/30