\(1+1=,,?????\)giup mik nha cac ban
Cac ban oi giup mik voi de thi ki 1 cua mik mong cac ban giup
S = 1 x 2+2x3+3x4+...39x40
S=...
Giup mik nha cac ban
3S=1x2x3+2x3x3+...+39x40x3
3S=1x2x(3-0)+2x3x(4-1)+...+39x40x(41-38)
3S=1x2x4-1x2x0+2x3x4-2x3x1+.....+39x40x41-38x39x40
3S=39x40x41
S=39x40x41:3
S=13x40x41
S=21320
S = 1 x 2 + 2 x 3 + 3 x 4 + ... + 39 x 40
S = 2 + 6 + 12 + ... + 1560
Sau đó tự làm nhé !
1) Tim 2 so a va b ( voi a > hoac = b ) biet rang a+b=270 va UCLN (a; b) = 45
GIUP MIK NHA CAC BAN MIK DANG CAN GAP LAM DAY CAC BAN IU
a : (x-\(\dfrac{1}{2}\))^2=0
b: (x-2)^2=1
c: (2x-1)^3=-8
d: (x+\(\dfrac{1}{2}\))^2=\(\dfrac{1}{16}\)
cac ban giup mik nha mik ko biet cach trinh bay
giup mik mik dang can gap
caam on cac ban nhieu
a) \(\left(x-\dfrac{1}{2}\right)^2=0\)
\(\Rightarrow x-\dfrac{1}{2}=0\)
\(\Rightarrow x=\dfrac{1}{2}\)
b) \(\left(x-2\right)^2=1\)
\(\Rightarrow x-2=1\)
\(\Rightarrow x=3\)
c) \(\left(2x-1\right)^3=-8\)
\(\Rightarrow\left(2x-1\right)^3=\left(-2\right)^3\)
\(\Rightarrow2x-1=-2\)
\(\Rightarrow2x=-1\)
\(\Rightarrow x=\dfrac{-1}{2}\)
d) \(\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{16}\)
\(\Rightarrow\left(x+\dfrac{1}{2}\right)^2=\left(\dfrac{1}{4}\right)^2\)
\(\Rightarrow\left[{}\begin{matrix}x+\dfrac{1}{2}=\dfrac{1}{4}\\x+\dfrac{1}{2}=-\dfrac{1}{4}\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{-1}{4}\\x=\dfrac{-3}{4}\end{matrix}\right.\).
a , \(\left(x-\dfrac{1}{2}\right)^2=0\)
<=> \(x-\dfrac{1}{2}=0\Rightarrow x=\dfrac{1}{2}\)
b , \(\left(x-2\right)^2=1\Rightarrow\left[{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=1\end{matrix}\right.\)
c , \(\left(2x-1\right)^3=-8\Rightarrow2x-1=-2\Rightarrow x=\dfrac{-1}{2}\)
d , \(\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{16}\Leftrightarrow\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{4^2}\)
<=> \(\left[{}\begin{matrix}x+\dfrac{1}{2}=\dfrac{1}{4}\\x+\dfrac{1}{2}=\dfrac{-1}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-1}{4}\\x=\dfrac{-3}{4}\end{matrix}\right.\)
a) \(\left(x-\dfrac{1}{2}\right)^2=0\)
\(\Leftrightarrow\left(x-\dfrac{1}{2}\right)^2=0^2\)
\(\Leftrightarrow x-\dfrac{1}{2}=0\)
\(\Leftrightarrow x=0+\dfrac{1}{2}\)
\(\Leftrightarrow x=\dfrac{1}{2}\left(TM\right)\)
Vậy \(x=\dfrac{1}{2}\) là giá trị cần tìm
b) \(\left(x-2\right)^2=1\)
\(\Leftrightarrow\left\{{}\begin{matrix}\left(x-2\right)^2=1^2\\\left(x-2\right)^2=\left(-1\right)^2\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x-2=1\\x-2=\left(-1\right)\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=3\\x=1\end{matrix}\right.\) \(\left(TM\right)\)
Vậy \(x\in\left\{3;1\right\}\)
c) \(\left(2x-1\right)^3=-8\)
\(\Rightarrow\left(2x-1\right)^3=\left(-2\right)^3\)
\(\Rightarrow2x-1=-2\)
\(\Rightarrow2x=-2+1\)
\(\Rightarrow2x=-1\)
\(\Rightarrow x=\dfrac{-1}{2}\left(TM\right)\)
Vậy \(x=\dfrac{-1}{2}\)
d) \(\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{16}\)
\(\Leftrightarrow\left\{{}\begin{matrix}\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{4}\\\left(x+\dfrac{1}{2}\right)^2=\dfrac{-1}{4}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x+\dfrac{1}{2}=\dfrac{1}{4}\\x+\dfrac{1}{2}=-\dfrac{1}{4}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{-1}{4}\\x=\dfrac{-3}{4}\end{matrix}\right.\)
Vậy \(x\in\left\{\dfrac{-1}{4};\dfrac{-3}{4}\right\}\) là giá trị cần tìm
a)tim x
1/(3x-1)2-(x+7)2=0
giup mik nha cac ban
Ta có : \(\left(3x-1\right)^2-\left(x+7\right)^2=0\)
\(\left(3x-1+x+7\right)\left(3x-1-x-7\right)=0\)
\(\left(4x+6\right)\left(2x-8\right)=0\)
Nên : 4x + 6 = 0 hoặc 2x - 8 = 0
4x = -6 hoặc 2x = 8
x = \(\frac{-3}{2}\) hoặc x = 4
Vậy x = \(\frac{-3}{2}\) hoặc x = 4
Hay viet 1 doan van bang tieng anh ke ve ban than minh .
Mik dang can gap, mong cac ban giup do.
Ai la ARMY kb voi mik nha .
My name is ....... and I’m a Vietnamese. I am ......... years old. I live in Ho Chi Minh city in the south of Vietnam.
I have a big family with four people. I have one sister and one brother. My sister is older and my brother is younger than me. My father is a teacher at a secondary school. He has worked for 35 years in the field and he is my biggest role model in life. My mother is a teacher too. She is very beautyful and she is really good at cooking. I love my family so much.
(I’m a generous and easy-going person but when it comes to work I’m a competitive perfectionist. I’m also an optimis and outgoing person so I have many friends and other social relationships. I enjoy reading, writing and doing math. I decided to become a Civil Engineer because I have always been fascinated by bridges, buildings, and skyscrapers. A degree in Civil Engineering enables me to achieve my goals and also gives me an opportunity to make a difference in the community.
Five years from now, I want to become a project manager of a construction project. As a project manager, my primary goals are managing people, set budgets, and making decisions of all kinds. I also want to speak English fluently so I can work with people from different countries.)
Bài tham khảo:
Hello everyone, my name is Le Ngoc Diep. This year I am 12 years old, I live in Dong Da, Hanoi. There are four members in my family, including my parents, elder brother and me. Now, I am studying in class 9B at Chu Van An school. At school I have a lot of friends, they are all docile and lovely. Everyone says that I am a very active and energe child so they love me so much. My favorite subject is Physics and English. My hobbies are cooking and reading books. Some of the favorite books are science fiction, detective, history and art. In my spare time, I also take an online piano course. In the future, I will try to get more experience to pursue the dream of becoming a famous pianist performing in the world.
cho sau chu so 1 2 3 5 7 9 tong cua cac so la
cac ban giup mik nha ai nhanh nhat minh tik cho
nho giai day du gium mik
cac ban oi ! giup mik voi ! ho mik bai nay di ! thu sau phai nop rui 1 ma ai lam cung duoc nhe!
de bai : hay sang tac mot bai tho noi ve " VIET TRI TRONG TRAI TIM EM " giup mik voi nha
xac dinh vi tri cua nguoi nguyen thuy sinh song tren trai dat
nho cac ban giup mik, tuy day la mon lich su nhung nho cac ban giup mik nha , tick cho, cam on
Vị trí : hang Thẩm Khuyên , Thẩm Hai (Lạng Sơn) ; Núi Đọ (Thanh Hóa); ..............................
thẩm khuyên,thẩm hai (lạng sơn), nui đọ(thanh hóa)