Tìm x
2+4+6+....+2x = 10100
Tìm x biết
2+4+6+...+2x=10100
\(2+4+6+...+2x=1010\)\(0\)
\(\Rightarrow2.\left(1+2+3+...+x\right)=10100\)
\(\Rightarrow1+2+3+...+n=10100:2=5050\)
\(\Rightarrow n.\left(n+1\right):2=5050\)
\(\Rightarrow n.\left(n+1\right)=5050.2=10100\)
\(\Rightarrow n.\left(n+1\right)=100.101\)
\(\Rightarrow n=100\)
\(2+4+6+.......+2x=10100.\)
\(2\cdot1+2\cdot2+2\cdot3+........+2x=10100\)
\(2\cdot\left(1+2+3+.....+x\right)=10100\)
\(1+2+3+....+x=10100:2\)
\(1+2+3+...+x=5050\)
\(\Rightarrow\left(x+1\right).\left(x-1+1\right):2=5050\)
\(\left(x+1\right).x:2=5050\)
\(\Rightarrow x.\left(x+1\right)=5050.2=10100\)
\(\text{Mà:}10100=2^2\cdot5^2\cdot101=100\cdot101\)
\(\Rightarrow x=100\)
Tìm x biết:
2+4+6+8+...+2x = 10100
Nho cac ban huong dan giai giup bai nay
A=2(1+2+3+.........+x)=10100
suy ra 1+2+3+.................+x=5050
\(\frac{x\left(x+1\right)}{2}\)=5050 \(\Rightarrow\)x2+x=10100\(\Rightarrow\)x2+x-10100=0\(\Rightarrow\)x=100 hoac x=-101 ma x>0 nen x=100
2 + 4 + 6 + ... + 2n = 10100
Tìm n
Ai tick cho mình tròn 40 với
Cảm ơn các bạn nhiều lắm
tìm số tự nhiên n thỏa mãn 2 + 4 + 6 + .... + 2n = 10100
\(2+4+6+.....+2n=10100\)
\(\Rightarrow\frac{\left(\left(2n-2\right):2+1\right).\left(2+2n\right)}{2}=10100\)
\(\Rightarrow\frac{\left(n-1+1\right).\left(2.\left(n+1\right)\right)}{2}=10100\)
\(\Rightarrow\frac{\left(n-0\right).2\left(n+1\right)}{2}=10100\)
\(\Rightarrow n.2\left(n+1\right)=10100.2=20200\)
\(\Rightarrow n.\left(n+1\right)=20200:2=10100\)
\(\Rightarrow n.\left(n+1\right)=101.100\)
\(\Rightarrow n=100\)
Vậy n = 100
Nhớ k cho mình nhé! Thank you!!!
Có :
2 + 4 + 6 +...+ 2.x = 10100
=> 2.( 1 + 2 + 3 +...+ n ) = 10100
=> 1 + 2 + 3 +...+ n = 10100 : 2 = 5050
=> n.(n+1) : 2 = 5050
=> n. ( n + 1 ) = 5050.2 = 10100
=> n. ( n + 1 ) = 100 . 101
=> n = 100
2+4+6+8+.....+2n=10100
2(1+2+3+4+....+n)=10100
1+2+3+4+....+n=10100:2
1+2+3+4+...+n=5050
\(\frac{\left(n+1\right)n}{2}\)=5050
(n+1)n=5050.2
(n+1)n=10100
(n+1)n=101.100
Vậy n=100
Chúc bạn học tốt
tìm số tự nhiên n thỏa mãn
2+4+6+8+...+2n=10100
n=100
các bạn cho mk vài li-ke cho tròn 600 với
tìm n biết : 2 + 4 + 6 +.......+2n = 10100
ai nhanh 3 tick ok
Ta có : 2 + 4 + 6 +... + 2n = 10100
=> 2(1 + 2 + 3 + ... + n) = 10100
=> 2n(n + 1) : 2 = 10100
=> n(n + 1) = 100.101
=> n = 100
Vậy n = 100
Lời giải:
2 + 4 + 6 + ....+ 2n = 10100
= 2 . ( 1 + 2 + 3 + .... + n) = 10100
= 2n. (n + 1) :2 = 10100
= n . (n + 1) = 100 . 101
=> n = 100
Vậy n=100
Chúc học tốt!!!
\(2+4+6+.....+2n=10100\)
\(\Leftrightarrow2\left(1+2+3+.....+n\right)=10100\)
\(\Leftrightarrow2.\frac{n\left(n+1\right)}{2}=10100\)\(\Leftrightarrow n\left(n+1\right)=10100=100.101\)
\(\Leftrightarrow n=100\)
Vậy \(n=100\)
tìm x:
a)3(2x-3)+2(2-x)=-3
b)2x(x2-2)+x2(1-2x)-x2=-12
c)3x(2x+3)-(2x+5)(3x-2)=8
d)4x(x - 1) - 3(x2-5)-x2=(x-3)-(x+4)
e)2(3x-1)(2x+5)-6(2x-1)(x+2)=-6
a: Ta có: \(3\left(2x-3\right)+2\left(2-x\right)=-3\)
\(\Leftrightarrow6x-9+4-2x=-3\)
\(\Leftrightarrow4x=2\)
hay \(x=\dfrac{1}{2}\)
B1: 48:(2x+6)+2014=2017
B2:x+2x,...,100x=10100
Bài 1: (2x+6)+2014=2017
=> 2x+6 = 2017-2014
=> 2x+6 = 3
=> 2x = -3
=> x = -3/2
Bài 2: x+2x+3x+.....+100x = 10100
=> x.(1+2+3+......+99+100) = 10100
=> x. 5050 = 10100
=> x = 10100 : 5050
=> x = 2
Vậy x = 2
Bài 1 :
\(48:\left(2x+6\right)+2014=2017\)
\(48:\left(2x+6\right)=2017-2014\)
\(48:\left(2x+6\right)=3\)
\(2x+6=48:3\)
\(2x+6=16\)
\(2x=16-6\)
\(2x=10\)
\(x=10:5\)
\(x=2\)
b) \(x+2x+3x+...+100x=10100\)
\(\Rightarrow1x+2x+3x+...+100x=10100\)
\(\Rightarrow x\cdot\left(1+2+3+...+100\right)=10100\)
\(\Rightarrow x\cdot\frac{\left(100+1\right)\cdot100}{2}=10100\)
\(\Rightarrow x\cdot5050=10100\)
\(\Rightarrow x=10100:5050\)
\(\Rightarrow x=2\)
Tìm x
1. x2 - 5x + 6 = 0
2. (x + 4)2 - (3x - 1)2 = 0
3, x2 - 2x + 24 = 0
4, 9x2 - 4 = 0
5, x2 + 2x - 8 = 0
1.
\(x^2-5x+6=0\\ \Rightarrow x^2-2x-3x+6=0\\ \Rightarrow\left(x^2-2x\right)-\left(3x-6\right)=0\\ \Rightarrow x\left(x-2\right)-3\left(x-2\right)=0\\ \Rightarrow\left(x-2\right)\left(x-3\right)=0\\ \Rightarrow\left[{}\begin{matrix}x-2=0\\x-3=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=2\\x=3\end{matrix}\right.\)
2.
\(\left(x+4\right)^2-\left(3x-1\right)^2=0\\ \Rightarrow\left(x+4-3x+1\right)\left(x+4+3x-1\right)=0\\ \Rightarrow\left(-2x+5\right)\left(4x+3\right)=0\\ \Rightarrow\left[{}\begin{matrix}-2x+5=0\\4x+3=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{5}{2}\\x=-\dfrac{3}{4}\end{matrix}\right.\)
3.
\(x^2-2x+24=0\\ \Rightarrow\left(x^2-2x+1\right)+23=0\\ \Rightarrow\left(x-1\right)^2+23=0\)
Vì (x-1)2≥0
23>0
\(\Rightarrow\left(x-1\right)^2+23>0\)
Vậy x vô nghiệm
4.
\(9x^2-4=0\\ \Rightarrow\left(3x-4\right)\left(3x+4\right)=0\\ \Rightarrow\left[{}\begin{matrix}3x-4=0\\3x+4=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{4}{3}\\x=-\dfrac{4}{3}\end{matrix}\right.\)
5.
\(x^2+2x-8=0\\ \Rightarrow\left(x^2+2x+1\right)-9=0\\ \Rightarrow\left(x+1\right)^2-3^2=0\\ \Rightarrow\left(x-2\right)\left(x+4\right)=0\\ \Rightarrow\left[{}\begin{matrix}x-2=0\\x+4=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=2\\x=-4\end{matrix}\right.\)