2x-2x+3x-4=26
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
2 tháng 7 2021
1) (2x + 1)(3x – 2) = (5x – 8)(2x + 1)
⇔ (2x + 1)(3x – 2) – (5x – 8)(2x + 1) = 0
⇔ (2x + 1).[(3x – 2) – (5x – 8)] = 0
⇔ (2x + 1).(3x – 2 – 5x + 8) = 0
⇔ (2x + 1)(6 – 2x) = 0
⇔\(\left[{}\begin{matrix}2x+1=0\\6-2x=0\end{matrix}\right.\) ⇔ \(\left[{}\begin{matrix}x=\dfrac{-1}{2}\\x=3\end{matrix}\right.\)
Vậy.....
2) 4x2 -1 = (2x + 1)(3x - 5)
⇔ (2x-1)(2x+1)-(2x+1)(3x-5)=0
⇔ (2x+1)(2x-1-3x+5)=0
⇔ (2x+1)(4-x)=0
⇔ \(\left[{}\begin{matrix}2x+1=0\\4-x=0\end{matrix}\right.\) ⇔ \(\left[{}\begin{matrix}x=\dfrac{-1}{2}\\x=4\end{matrix}\right.\)
Vậy...
3)
(x + 1)2 = 4(x2 – 2x + 1)
⇔ (x + 1)2 - 4(x2 – 2x + 1) = 0
⇔ x2 + 2x +1- 4x2 + 8x – 4 = 0
⇔ - 3x2 + 10x – 3 = 0
⇔ (- 3x2 + 9x) + (x – 3) = 0
⇔ -3x (x – 3)+ ( x- 3) = 0
⇔ ( x- 3) ( - 3x + 1) = 0
⇔\(\left[{}\begin{matrix}x-3=0\\-3x+1=0\end{matrix}\right.\) ⇔\(\left[{}\begin{matrix}x=3\\x=\dfrac{1}{3}\end{matrix}\right.\)
Vậy......
H9
HT.Phong (9A5)
CTVHS
24 tháng 7 2023
a) \(2^x\cdot4=128\)
\(\Rightarrow2^x\cdot2^2=2^7\)
\(\Rightarrow2^{x+2}=2^7\)
\(\Rightarrow x+2=7\)
\(\Rightarrow x=5\)
b) \(\left(2x+1\right)^3=125\)
\(\Rightarrow\left(2x+1\right)^3=5^3\)
\(\Rightarrow2x+1=5\)
\(\Rightarrow2x=4\)
\(\Rightarrow x=4:2\)
\(\Rightarrow x=2\)
c) \(2x-2^6=6\)
\(\Rightarrow2x-64=6\)
\(\Rightarrow2x=70\)
\(\Rightarrow x=70:2\)
\(\Rightarrow x=35\)
d) \(64\cdot4^x=45\)
\(\Rightarrow4^3\cdot4^x=45\)
\(\Rightarrow4^{x+3}=45\)
Xem lại đề
e) \(27\cdot3^x=243\)
\(\Rightarrow3^3\cdot3^x=3^5\)
\(\Rightarrow3^{x+3}=3^5\)
\(\Rightarrow x+3=5\)
\(\Rightarrow x=2\)
g) \(49\cdot7^x=2401\)
\(\Rightarrow7^2\cdot7^x=7^4\)
\(\Rightarrow7^{x+2}=7^4\)
\(\Rightarrow x+2=4\)
\(\Rightarrow x=2\)
h) \(3^x=81\)
\(\Rightarrow3^x=3^4\)
\(\Rightarrow x=4\)
k) \(3^4\cdot3^x=3^7\)
\(\Rightarrow3^{x+4}=3^7\)
\(\Rightarrow x+4=7\)
\(\Rightarrow x=3\)
n) \(3^x+25=26\cdot2^2+2\cdot3^0\)
\(\Rightarrow3^x+25=104+2\)
\(\Rightarrow3^x+25=106\)
\(\Rightarrow3^x=81\)
\(\Rightarrow3^x=3^4\)
\(x=4\)
24 tháng 7 2023
`@` `\text {Ans}`
`\downarrow`
`a)`
`2^x*4 = 128`
`=> 2^x = 128 \div 4`
`=> 2^x = 2^7 \div 2^2`
`=> 2^x = 2^5`
`=> x = 5`
Vậy, `x = 5.`
`b)`
\(\left(2x+1\right)^3=125\)
`=> (2x + 1)^3 = 5^3`
`=> 2x + 1 = 5`
`=> 2x = 5-1`
`=> 2x = 4`
`=> x = 4 \div 2`
`=> x = 2`
Vậy, `x = 2`
`c)`
\(2x-2^6=6\)
`=> 2x = 6+2^6`
`=> 2x = 70`
`=> x = 70 \div 2`
`=> x = 35`
Vậy, `x = 35`
`d)`
\(64\cdot4^x=45\) Bạn xem lại đề
`e)`
`27*3^x = 243`
`=> 3^3 * 3^x = 3^5`
`=> 3^(3 + x) = 3^5`
`=> 3 + x = 5`
`=> x = 5 - 3`
`=> x = 2`
Vậy, `x = 2`
`g)`
`49* 7^x = 2401`
`=> 7^2 * 7^x = 7^4`
`=> 7^(2 + x) = 7^4`
`=> 2 + x = 4`
`=> x = 4 - 2`
`=> x = 2`
Vậy, `x = 2`
`h)`
`3^x = 81`
`=> 3^x = 3^4`
`=> x = 4`
Vậy, `x = 4`
`k)`
`3^4 * 3^x = 3^7`
`=> 3^(4 + x) = 3^7`
`=> 4 + x = 7`
`=> x = 7 - 4`
`=> x = 3`
Vậy, `x = 3`
`n)`
`3^x + 25 = 26*2^2 + 2*3^0`
`=> 3^x + 25 = 104 + 2`
`=> 3^x + 25 = 106`
`=> 3^x = 106 - 25`
`=> 3^x = 81`
`=> 3^x = 3^4`
`=> x = 4`
Vậy, `x = 4.`
\(#48Cd\)
D
6 tháng 8 2021
\(4\left(x+1\right)\left(-x+2\right)+\left(2x-1\right)\left(2x+3\right)=-11\)
\(\text{⇔}-4x^2+4x+8+4x^2+4x-3=-11\)
\(\text{⇔}8x+5=-11\)
\(\text{⇔}8x=-16\)
\(\text{⇔}x=-2\)
Vậy: \(x=-2\)
==========
\(\left(2x+4\right)\left(3x+1\right)\left(x-2\right)-\left(-3x^2+1\right)\left(-2x+\dfrac{2}{3}\right)=-\dfrac{26}{3}\)
\(\text{⇔}6x^3+2x^2-24x-8-6x^3-2x^2-2x+\dfrac{2}{3}=-\dfrac{26}{3}\)
\(\text{⇔}-26x-\dfrac{22}{3}=-\dfrac{26}{3}\)
\(\text{⇔}-26x=-\dfrac{4}{3}\)
\(\text{⇔}x=\dfrac{2}{39}\)
NN
3
25 tháng 9 2021
a) \(\Rightarrow2^x=32\Rightarrow2^x=2^5\Rightarrow x=5\)
b) \(\Rightarrow\left(2x+1\right)^3=5^3\)
\(\Rightarrow2x+1=5\Rightarrow x=2\)
c) \(\Rightarrow2^x=32\Rightarrow x=5\)
d) \(\Rightarrow4^3.4^x=4^5\Rightarrow4^x=4^2\Rightarrow x=2\)
e) \(\Rightarrow3^3.3^x=3^5\Rightarrow3^x=3^2\Rightarrow x=2\)
f) \(\Rightarrow7^2.7^x=7^4\Rightarrow7^x=7^2\Rightarrow x=2\)
HP
25 tháng 9 2021
a. 2x . 4 = 128
<=> 2x + 2 = 27
<=> x + 2 = 7
<=> x = 5
b. (2x + 1)3 = 125
<=> (2x + 1)3 - 53 = 0
<=> (2x + 1 - 5)\(\left[\left(2x+1\right)^2+\left(2x+1\right).5+25\right]=0\)
<=> (2x - 4)(4x2 + 4x + 1 + 10x + 5 + 25) = 0
<=> (2x - 4)(4x2 + 14x + 31) = 0
<=> \(\left[{}\begin{matrix}2x-4=0\\4x^2+14x+31=0\end{matrix}\right.\)
<=> \(\left[{}\begin{matrix}x=2\\VôNghiệm\end{matrix}\right.\)
c. 2x - 26 = 6
<=> 2x = 32
<=> x = 5
d. 64 . 4x = 45
<=> 43 . 4x = 45
<=> 43 + x = 45
<=> 3 + x = 5
<=> x = 2
e. 27 . 3x = 243
<=> 33 . 3x = 35
<=> 33 + x = 35
<=> 3 + x = 5
<=> x = 2
g. 49 . 7x = 2401 (Bn xem lại đề câu này)
<=> 72 . 7x = 74
<=> 72 + x = 74
<=> 2 + x = 4
<=> x = 2
GP
2
6 tháng 8 2021
x=\(\dfrac{11}{2}\)=5\(\dfrac{1}{2}\)=5.5x=0
HT
1
22 tháng 6 2017
a)\(5\left(2x-1\right)-4\left(8-3x\right)=7\)
\(\Leftrightarrow10x-5+12x-32=7\)
\(\Leftrightarrow22x-37=7\)
\(\Leftrightarrow22x=44\Rightarrow x=2\)
b)\(5x\left(x-5\right)-x\left(2x+3\right)=26\)
\(\Leftrightarrow5x^2-25x-2x^2-3x=26\)
\(\Leftrightarrow3x^2-28x-26=0\)
\(\Leftrightarrow3\left(x-\dfrac{14}{3}\right)^2-\dfrac{274}{3}=0\)
\(\Rightarrow x=\dfrac{14}{3}\pm\dfrac{\sqrt{274}}{3}\)
HP
1
18 tháng 6 2023
b: Δ=(-12)^2-4*2*(9+4căn 2)
=144-72-32căn 2=72-32căn 2
=(8-2căn 2)^2
=>PT có hai nghiệm pb là:
\(\left\{{}\begin{matrix}x=\dfrac{12-8+2\sqrt{2}}{4}=\dfrac{2+\sqrt{2}}{2}\\x_2=\dfrac{2-\sqrt{2}}{2}\end{matrix}\right.\)
c: Δ=(-30)^2-4*3*(-26+8căn 3)
=900+312-96căn 3
=1212-2*căn 3072
=>Phương trình có hai nghiệm pb là:
\(\left\{{}\begin{matrix}x=\dfrac{30-2\sqrt{1212-2\sqrt{3072}}}{6}\\x=\dfrac{30+2\sqrt{1212-2\sqrt{3072}}}{6}\end{matrix}\right.\)
2x-2x+3x-4=26
=>3x-4=26
=>3x=30
=>\(x=\dfrac{30}{3}=10\)
`#3107.101107`
`2x - 2x + 3x - 4 = 26`
`\Rightarrow x(2 - 2 + 3) - 4 = 26`
`\Rightarrow 3x - 4 = 26`
`\Rightarrow 3x = 26 + 4`
`\Rightarrow 3x = 30`
`\Rightarrow x = 30 \div 3`
`\Rightarrow x = 10`
Vậy, `x = 10.`