Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1/ 3(x - 2) = 9 => x - 2 = 3 => x = 5
2/ 3(x - 36) = 216 => x - 36 = 72 => x = 108
3/ (x - 3)3 = 33 => x - 3 = 3 => x = 6
4/ 2x = 32 => 2x = 25 => x = 5
5/ 3x - 16 = 2.74 : 73 = 14 => 3x = 30 => x = 10
6/ (6x - 39) : 3 = 201 => 6x - 39 = 603 => 6x = 642 => x = 107
7/ (3x - 15)2 = 81 => (3x - 15)2 = 92 => 3x - 15 = 9 => 3x = 24 => x = 8
8/ 3(x + 4) = 105 => x + 4 = 35 => x = 31
9/ 12x - 43 = 4.84 : 83 = 32 => 12x = 32 : 64 => 12x = 1/2 => x = 1/24
10/ 41 - (2x - 5) = 680 => 2x - 5 = -639 => 2x = -634 => x = - 317
Bài 1 :
a/ \(a^3.a^9=a^{3+9}=a^{12}\)
b/\(\left(a^5\right)^7=a^{5.7}=a^{35}\)
c/ \(\left(a^6\right).4.a^{12}=a^{24}.a^{12}.4=a^{24+12}.4=a^{36}.4\)
d/ \(\left(2^3\right)^5.\left(2^3\right)^3=2^{15}.2^9=2^{15+9}=2^{24}\)
e/ \(5^6:5^3+3^3.3^2\)
\(=5^3+3^5=125+243=368\)
i/ \(4.5^2-2.3^2\)
\(=2^2.5^2-2.3^2\)
\(=2^2.25-2^2.14\)
\(=2^2.\left(25-14\right)\)
\(=2^2.11\)
\(=4.11=44\)
\(\left(12x-4^3\right).8^3=4.8^4\)
\(12x-4^3=4.8^4:8^3\)
\(12x-64=4.8\)
\(12x-64=32\)
\(12x=32+64=96\)
\(x=96:12=8\)
Vậy x=8
\(b.\left(\left(4x+28\right).3+55\right):5=35\)
\(\left(4x+28\right).3+55=35\times5\)
\(\left(4x+28\right).3+55=175\)
\(\left(4x+28\right).3=175-55\)
\(\left(4x+28\right).3=120\)
\(4x+28=120:3=40\)
\(4x=40-28=12\)
\(x=12:4=3\)
Vậy x=3
\(c.720:\left(41-\left(2x-5\right)\right)=2^3.5\)
\(720:\left(41-\left(2x-5\right)\right)=40\)
\(41-\left(2x-5\right)=720:40=18\)
\(2x-5=41-18=23\)
\(2x=23+5=28\)
\(x=28:2=14\)
Vậy x=14
\(d.\left(3x-2^4\right).7^3=2.7^4\)
\(\left(3x-16\right).7^3=2.7^4\)
\(3x-16=2.7^4:7^3\)
\(3x-16=2.7=14\)
\(3x=14+16=30\)
\(x=30:3=10\)
Vậy x=10
Nhớ k cho mình nhé! Thank you!!!
Đặt \(A=5+5^3+5^5+....+5^{47}+5^{49}\)
\(\Rightarrow5^2A=5^3+5^5+5^7+.....+5^{49}+5^{51}\)
\(\Rightarrow5^2A-A=\left(5^3+5^5+5^7+....+5^{49}+5^{51}\right)-\left(3+3^3+3^5+....+5^{47}+5^{49}\right)\)
\(\Rightarrow24A=5^{51}-5\)
\(\Rightarrow A=\dfrac{5^{51}-5}{24}\)
Vậy ............................................................
1)a) \(\left(3x-7\right)^5=32\Rightarrow\left(3x-7\right)^5=2^5\)
\(\Rightarrow3x-7=2\Rightarrow3x=9\Rightarrow x=3\)
Vậy \(x=3\)
b) \(\left(4x-1\right)^3=-27.125\)
\(\Rightarrow\left(4x-1\right)^3=-3^3.5^3=-15^3\)
\(\Rightarrow4x-1=-15\Rightarrow4x=-14\Rightarrow x=-3,5\)
Vậy \(x=-3,5\)
c) \(3^{4x+4}=81^{x+3}\Rightarrow3^{4x+4}=3^{4x+12}\)
\(\Rightarrow4x+4=4x+12\)
\(\Rightarrow4x=4x+8\)
\(\Rightarrow x\in\varnothing\)
d) \(\left(x-5\right)^7=\left(x-5\right)^9\)
\(\Rightarrow\left(x-5\right)^7-\left(x-5\right)^9=0\)
\(\Rightarrow\left(x-5\right)^7.\left[1-\left(x-5\right)^2\right]=0\)
\(\Rightarrow\left[{}\begin{matrix}\left(x-5\right)^7=0\\1-\left(x-5\right)^2=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=5\\\left(x-5\right)^2=1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=5\\x-5=-1\\x-5=1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=5\\x=4\\x=6\end{matrix}\right.\)
Vậy \(\left[{}\begin{matrix}x=5\\x=4\\x=6\end{matrix}\right.\)
Theo đề bài ta có:
(x.5+16):3=7
x.5+16 =7.3
x.5+16 =21
x.5 =21-16
x.5 =5
x =5:5
x =1
Vậy x=1
a) (x : 3 - 4) . 5 = 15
x : 3 - 4 = 15 : 5
x : 3 - 4 = 3
x : 3 = 3 + 4
x : 3 = 7
x = 7 . 3
x = 21.
b) 128 - 3 . (x + 4) = 23
3 . (x + 4) = 128 - 23
3 . (x + 4) = 105
x + 4 = 105 : 3
x + 4 = 35
x = 35 - 4
x = 31.
c) (3x - 24) . 73 = 2 . 74
3x - 24 = 2 . 74 : 73
3x - 24 = 2 . 7
3x - 16 = 14
3x = 14 + 16
3x = 30
x = 30 : 3
x = 10.
d) 5x + x = 39 - 311 : 39
5x + x = 39 - 32
5x + x = 39 - 9
6x = 30
x = 30 : 6
x = 5.
a) \(\left(\dfrac{x}{3}-4\right).5=15\)
\(\Leftrightarrow\dfrac{x}{3}-4=\dfrac{15}{5}\)
\(\Leftrightarrow\dfrac{x}{3}-4=3\)
\(\Leftrightarrow\dfrac{x}{3}=3+4\)
\(\Leftrightarrow\dfrac{x}{3}=7\)
\(\Leftrightarrow x=7.3\)
\(\Leftrightarrow x=21\)
Vậy \(x=21\)
b) \(128-3\left(x+4\right)=23\)
\(\Leftrightarrow3\left(x+4\right)=128-23\)
\(\Leftrightarrow3\left(x+4\right)=105\)
\(\Leftrightarrow x+4=\dfrac{105}{3}\)
\(\Leftrightarrow x+4=35\)
\(\Leftrightarrow x=35-4\)
\(\Leftrightarrow x=31\)
Vậy \(x=31\)
c) \(\left(3x-2^4\right).7^3=2.7^4\)
\(\Leftrightarrow3x-2^4=\dfrac{2.7^4}{7^3}\)
\(\Leftrightarrow3x-2^4=2.7\)
\(\Leftrightarrow3x-2^4=14\)
\(\Leftrightarrow3x-16=14\)
\(\Leftrightarrow3x=14+16\)
\(\Leftrightarrow3x=30\)
\(\Leftrightarrow x=\dfrac{30}{3}\)
\(\Leftrightarrow x=10\)
Vậy \(x=10\)
d) \(5x+x=39-3^{11}:3^9\)
\(\Leftrightarrow6x=39-3^{11-9}\)
\(\Leftrightarrow6x=39-3^2\)
\(\Leftrightarrow6x=39-9\)
\(\Leftrightarrow6x=30\)
\(\Leftrightarrow x=\dfrac{30}{6}\)
\(\Leftrightarrow x=5\)
Vậy \(x=5\)
a) \(\frac{18^4.3^2.8^3}{27^3.16^2}=\frac{\left(2.3^2\right)^4.3^2.\left(2^3\right)^3}{\left(3^3\right)^3.\left(2^4\right)^2}=\frac{2^4.2^9.3^8.3^2}{3^9.2^8}=\frac{2^{13}.3^{10}}{3^9.2^8}=3.2^5=96\)
b) \(\frac{35^5.9^3.8^5}{81^4.32^5}=\frac{35^5.\left(3^2\right)^3.\left(2^3\right)^5}{\left(3^4\right)^4.\left(2^5\right)^5}=\frac{35^5.3^6.2^{15}}{3^{16}.2^{25}}=\frac{35^5}{3^{10}.2^{10}}=\frac{35^5}{6^{10}}\)
c) \(\frac{48^5.18^2}{81^2.34^4}=\frac{\left(2^4.3\right)^5.\left(2.3^2\right)^2}{\left(3^4\right)^2.\left(2.17\right)^4}=\frac{2^{20}.3^5.2^2.3^4}{3^8.2^4.17^4}=\frac{2^{22}.3^9}{3^8.2^4.17^4}=\frac{2^{18}.3}{17^4}\)
d) \(\frac{54^7.27^3.16^2}{243^2.64^3}=\frac{\left(2.3^3\right)^7.\left(3^3\right)^3.\left(2^4\right)^2}{\left(3^5\right)^2.\left(2^6\right)^3}=\frac{2^7.3^{21}.3^9.2^8}{3^{10}.2^{18}}=\frac{2^{15}.3^{30}}{3^{10}.2^{18}}=\frac{3^{20}}{2^3}\)