2 + 4 + 6 + 8 + ... + 2 x ( x + 1 ) = 61752 vậy x = .........
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=> 2.(1 + 2 + 3 + 4 + ...+ (x+1)) = 61 752
=> 1 + 2+ 3 + 4 + ...+ (x+1) = 61 752 : 2
=> (1 + x+ 1) .(x+1): 2 = 61 752 : 2
=> (x+2)(x+1) = 61 752 = 249.248 => x+ 1 = 248 => x = 247
2 + 4 + 6 + 8 + ... + 2(x + 1) = 61752
2.1 + 2.2 + 2.3 + ... + 2(x + 1) = 61752
2.[1 + 2 + 3 + ... + (x + 1)] = 61752
{[(x + 1) - 1]:1 + 1} . [(x + 1) + 1]:2 = 61752:2
(x + 1).(x + 2) = 61752:2.2
(x + 1)(x + 2) = 61752
Ta có: 61752 = 248.249
=> (x + 1)(x + 2) = 248.249
=> x + 1 = 248
x = 248 - 1
x = 247
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Bạn bấm vào dòng chữ màu xanh này nhé Pham Tien Dat
If 2 + 4 + 6 + 8 +........+ 2 x - Giúp tôi giải toán - Hỏi đáp, thảo ...
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được rồi tôi giải 2+4+6+8+10+2(x+1)=61752 tôi giải rồi tich đi
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2+4+6+8+…+2.(x+1)=61752
=>2.[1+2+3+4+…+(x+1)]=61752
=>\(2.\frac{\left(x+1\right).\left(x+1+1\right)}{2}=61752\)
=>(x+1).(x+2)=61752=248.249
=>(x+1).(x+2)=(247+1).(247+2)
=>x=247
Vậy x=247
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\(\Leftrightarrow-\dfrac{5}{8}\cdot\dfrac{5}{3}< x< \dfrac{6}{25}\cdot\dfrac{25}{4}\)
=>-25/24<x<6/4
mà x là số tự nhiên
nên \(x\in\left\{0;1\right\}\)
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\(\dfrac{8}{9}\) : ( 2 - 3 \(\times\) y) = \(\dfrac{5}{3}\)
2 - 3 \(\times\) y = \(\dfrac{8}{9}\) : \(\dfrac{5}{3}\)
2 - 3 \(\times\) y = \(\dfrac{8}{15}\)
3 \(\times\) y = 2 - \(\dfrac{8}{15}\)
3 \(\times\) y = \(\dfrac{22}{15}\)
y = \(\dfrac{22}{15}\) : 3
y = \(\dfrac{22}{45}\)
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1: x=3/4-1/2=3/4-2/4=1/4
2: x-1/5=2/11
=>x=2/11+1/5=21/55
3: x-5/6=16/42-8/56
=>x-5/6=8/21-4/28=5/21
=>x=5/21+5/6=15/14
4: x/5=5/6-19/30
=>x/5=25/30-19/30=6/30=1/5
=>x=1
5: =>|x|=1/3+1/4=7/12
=>x=7/12 hoặc x=-7/12
6: x=-1/2+3/4
=>x=3/4-1/2=1/4
11: x-(-6/12)=9/48
=>x+1/2=3/16
=>x=3/16-1/2=-5/16
1)x= 1/4
2)x= 2/11+ 1/5
x= 21/55
3)x - 5/6 = 5/21
x = 5/21+5/6
x = 15/14
4)x/5 = 5/6 + -19/30
x:5 = 1/5
x = 1/5.5
x = 1
5) |x| - 1/4 = 6/18
|x| = 6/18 - 1/4
|x| =7/12
⇒x= 7/12 hoặc -7/12
6)x = -1/2 +3/4
x= 1/4
7) x/15 = 3/5 + -2/3
x:15 = -1/15
x = -1/15. 15
x = -1
8)11/8 + 13/6 = 85/x
85/24 = 85/x
⇒ x = 24
9) x - 7/8 = 13/12
x = 13/12 + 7/8
x = 47/24
10)x - -6/15 = 4/27
x = 4/27 + (-6/15)
x = -34/135
11) -(-6/12)+x = 9/48
x= 9/48 - 6/12
x = -5/16
12) x - 4/6 = 5/25 + -7/15
x -4/6 = -4/15
x = -4/15 + 4/6
x = 2/5