2.(1/2x-1/3)-3/2=1/4
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
A = 1 + 2 + 22 + 23+......+29
2A = 2+ 22 + 23 +.......+29 + 210
2A - A = 210 -1
A = 210 - 1
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
22x+1 + 22x+2 = 3.211
22x+1 (1 +2) = 3.211
22x+1..3 = 3,211
22x+1 = 211
2x + `1 = 11
2x = 10
x = 10: 2
x = 5
![](https://rs.olm.vn/images/avt/0.png?1311)
đặt tổng trên là A
\(2A=2+2^2+2^3+...+2^{10}\)
\(A=2A-A=2^{10}-1\)
![](https://rs.olm.vn/images/avt/0.png?1311)
(351 - 875) - (125 - 149)
= 351 - 875 - 125 + 149
= (351 + 149) - (875 + 125)
= 500 - 1000
= -500
![](https://rs.olm.vn/images/avt/0.png?1311)
\(3A=1.2.3+2.3.3+3.4.3+...+99.100.3=\)
\(=1.2.3+2.3.\left(4-1\right)+3.4.\left(5-2\right)+...+99.100.\left(101-98\right)=\)
\(=1.2.3-1.2.3+2.3.4-2.3.4+3.4.5-...-98.99.100+99.100.101=\)
\(=99.100.101\Rightarrow A=33.100.101\)
A = 1.2 + 2.3 + 3.4 +........+99.100
3 x A = 1.2.3+2.3.3 +3.4.3+....99.100.3
3xA = 1.2.3+2.3.(4-1) + 3.4.(5-2) +4.5.(6-3)+....+99.100(101-98)
3xA = 1.2.3 -1.2.3 +2.3.4 - 2.3.4 +3.4.5 - 3.4.5+....+99.100.101
3xA = 99.100.101
A = 99.100.101 : 3
A = 33.100.101
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
2( \(\dfrac{1}{2}\) x - \(\dfrac{1}{3}\)) - \(\dfrac{3}{2}\) = \(\dfrac{1}{4}\)
2(\(\dfrac{1}{2}\)x - \(\dfrac{1}{3}\)) = \(\dfrac{1}{4}\) + \(\dfrac{3}{2}\)
2(\(\dfrac{1}{2}\)x - \(\dfrac{1}{3}\)) = \(\dfrac{7}{4}\)
\(\dfrac{1}{2}\)x = \(\dfrac{7}{4}\) : 2 + \(\dfrac{1}{3}\)
\(\dfrac{1}{2}\)x = \(\dfrac{29}{24}\)
x = \(\dfrac{29}{24}\) x2
x = \(\dfrac{29}{12}\)
`2.(1/2 x - 1/3) - 3/2 = 1/4`
`2.(1/2 x - 1/3) = 1/4 + 3/2`
`2.(1/2 x - 1/3) = 1/4 + 6/4`
`2.(1/2 x - 1/3) = 7/4`
`1/2x - 1/3 = 7/4 : 2`
`1/2 x - 1/3 = 7/4 xx 1/2`
`1/2 x - 1/3 = 7/8`
`1/2 x = 7/8 + 1/3`
`1/2 x = 21/28 + 7/28`
`1/2 x = 29/24`
`x=29/24 : 1/2`
`x=29/24 xx 2`
`x=29/12`
Vậy `x = 29/12`