2^x+3.2^x=144
x.(x-2)= 16; 2 mũ x+3.2 mũ x=144
\(x\)(\(x\) - 2) = 16
\(x^2\) - 2\(x\) - 16 = 0
(\(x^2\) - \(x\)) - (\(x\) - 1) - 17 = 0
\(x\)(\(x\) - 1) - (\(x-1\)) = 17
(\(x\) - 1)(\(x\) - 1) = 17
(\(x-1\))2 = 17
\(\left[{}\begin{matrix}x-1=\sqrt{17}\\x-1=-\sqrt{17}\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=1+\sqrt{17}\\x=1-\sqrt{17}\end{matrix}\right.\)
Vậy: \(\in\) {1 - \(\sqrt{17}\); 1 + \(\sqrt{17}\)}
Bài 2:
2\(x\) + 3.2\(x\) = 144
2\(x\).(1 + 3) = 144
2\(x\).4 = 144
2\(x\) = 144 : 4
2\(x\) = 36
2\(^x\) = 36
Nếu \(x\) = 6 ⇒ 2\(^x\) = 64 > 36 (loại)
Nếu \(x\) ≤ 5 ⇒2\(^x\) ≤ 25 = 32 < 36 (loại)
Vậy \(x\in\) \(\varnothing\)
a) (4.x+5):3-121:11=4
b)2x+2x+3=144
c)10{[(x:3+17):10+3.22]:10}=5
c) 10 . {[(x : 3 + 17) : 10 + 3 . 2^2] : 10} = 5
[(x : 3 + 17) : 10 + 3 . 4] : 10 = 5 : 10
[(x : 3 + 17) : 10 + 12] : 10 = 1/2
(x : 3 + 17) : 10 + 12 = 1/2 . 10
(x : 3 + 17) : 10 + 12 = 5
(x : 3 + 17) : 10 = 5 - 12
(x : 3 + 17) : 10 = -7
=> x : 3 + 17 = -7 . 10
x : 3 + 17 = -70
x : 3 = -70 - 17
x : 3 = -87
x = -87 . 3
x = -261
a ) \(\left(4x+5\right):3-121:1=4\)
\(\Leftrightarrow\left(4x+5\right):3-11=4\)
\(\Leftrightarrow\left(4x+5\right):3=15\)
\(\Leftrightarrow\left(4x+5\right)=45\)
\(\Leftrightarrow4x=40\)
\(\Leftrightarrow x=10\)
Tiếp tịch như z là đc
a, (4.x+5)/3-121/11=4
(4.x+5)/3-11=4
(4.x+5)/3=4+11
(4.x+5)/3=15
4.x+5=15/3
4.x+5=5-----4.x=5-5----4.x=0---x=0/4---x=0
b,2^x+n^x+3=144
2^x+2^x.2^3=144
2^x.(1+2^3)=144
2^x.(1+8)=144
2^x.9=144---2^x=144/9------2^x=16=2^4---x=4
câu c tự làm dài quá tớ ko làm kịp tu la nha
Tìm só tự nhên x, biết rằng;
a) (4x + 5) : 3 - 121 : 11= 4
b) 2 mủ x + 2 mủ x + 3= 144
c) 10 - {[( x : 3+ 17): 10+ 3.2 mủ 4]: 10} = 5
ba bài giúp mih vs nhé!!!! trl nhanh nhất có thể nha .... cảm ơn
a)(4x+5):3 -121:11=4
(4x+5):3-11=4
(4x+5):3=15
4x+5=45
4x=40
x=10
Vậy x=10
b)2^x+2^x+3=144
2^x(1+2^3)=144
2^x.9=144
2^x=16
x=4
Vậy x=4
c)10-{[(x:3+17):10+3.2^4]:10}=5
[(x:3+17):10+3.16]:10=5
(x:3+17):10+4=50
(x:3+17):10=46
x:3+17=460
x:3=443
x=1329
Vậy x=1329
a)(4x+5):3 - 121=4x11 (4x+5):3 - 121=44 (4x+5):3 = 44+121 (4x+5):3 = 165 4x+5 = 165 :3 4x+5 = 55 4x = 55 - 5 4x = 50 x= 50x4 x=200
(4x +5):3 - 121: 11= 4
đề như vầy nhé pạn giúp mih với...... còn 2 bài pạn giúp mình lun nhé ...cảm ơn pan An Dương
Tìm x biết
10 + 2 . x = 4⁵ : 4³
2 x - 6² : 18 = 3.2²
70 - 5 . ( x- 3 ) = 3.2
\(10+2\cdot x=4^5:4^3\)
\(\Rightarrow10+2\cdot x=4^{5-3}\)
\(\Rightarrow10+2\cdot x=4^2\)
\(\Rightarrow10+2\cdot x=16\)
\(\Rightarrow2\cdot x=16-10\)
\(\Rightarrow2\cdot x=6\)
\(\Rightarrow x=\dfrac{6}{2}=3\)
__________________
\(2\cdot x-6^2:18=3\cdot2^2\)
\(\Rightarrow2\cdot x-36:18=12\)
\(\Rightarrow2\cdot x-2=12\)
\(\Rightarrow2\cdot x=12+2\)
\(\Rightarrow2\cdot x=14\)
\(\Rightarrow x=\dfrac{14}{2}=7\)
_________________
\(70-5\cdot\left(x-3\right)=3\cdot2\)
\(\Rightarrow70-5\cdot\left(x-3\right)=6\)
\(\Rightarrow70-5x+15=6\)
\(\Rightarrow-5x+15=6-70\)
\(\Rightarrow-5x+15=64\)
\(\Rightarrow-5x=64-15\)
\(\Rightarrow-5x=49\)
\(\Rightarrow x=-\dfrac{49}{5}\)
bài 1. tìm x biết.
a) 32^n.16^n=1024
b) 9.27^x=3^5
c) 2^x+3.2^n=144
d) 2^x+1.3^y
Nhanh đúng mik tik
tính: 2015(144-1^2)x(144-2^2)x...........x(144-20^2)
Tim x
a,-2/3(x-1/4)=1/3(2x-1)
b,1/5.2^x +1/3.2^x+1=1/5.2^7 +1/3.2^8
giup mink ai nhanh tick 3 lan nghia la 1 lan tra loi mot lan noi lam rui mot lan noi cam on
`(3.2^(x+1))/(2.2^(x+2))`
\(=\dfrac{3\cdot2^{x+1}}{2^{x+3}}=\dfrac{3}{2^2}=\dfrac{3}{4}\)
\(2^{x-3}-3.2^x=-92\)
\(2^{x-3}-3.2^x=-92\)
\(\Rightarrow2^x\left(2^{-3}-3\right)=-92\)
\(\Rightarrow2^x.\dfrac{-23}{8}=-92\Rightarrow2^x=32\)
\(\Rightarrow2^x=2^5\Rightarrow x=5\)