tìm x
câu 1 : 5^x+4-3.5^x+3=2.5^11
câu 2 : 2.3^x+2+4.3^x+1=10.3^6
câu 3 :6.8^x-1+8^x+1=6.8^19+8^2
giúp tớ nha . Cảm ơn
A)2.3x+2+4.3x+1=10.36
B)6.8x-1+8x+1=6.819+821
C)4.3x-2+2.3x+1=4.34+2.37
(lưu ý dấu (.) là nhân)
Giúp mình với!!!
A) \(2.3^{x+2}+4.3^{x+1}=10.3^6\)
=> \(2.3.3^{x+1}+4.3^{x+1}=10.3^6\)
=> \(6.3^{x+1}+4.3^{x+1}=10.3^6\)
=> \(\left(6+4\right).3^{x+1}=10.3^6\)
=> \(10.3^{x+1}=10.3^6\)
=> \(3^{x+1}=3^6\)
=> \(x+1=6\)
=> \(x=6-1\)
=> \(x=5\)
Vậy \(x=5.\)
B) \(6.8^{x-1}+8^{x+1}=6.8^{19}+8^{21}\)
=> \(6.8^{x-1}+8^{x-1}.8^2=6.8^{19}+8^{19}.8^2\)
=> \(8^{x-1}.\left(6+8^2\right)=8^{19}.\left(6+8^2\right)\)
=> \(8^{x-1}=8^{19}\)
=> \(x-1=19\)
=> \(x=19+1\)
=> \(x=20\)
Vậy \(x=20.\)
Còn câu c) thì mình đang nghĩ nhé.
Chúc bạn học tốt!
Tìm số nguyên x, biết :
a) 5x = 54. 58.
b) 5x+4 -3.5x+3 = 2.511.
c) 6.8x-1 + 8 . x+1 = 6.819 + 821.
tim so nguyen x biet
a)5x=54.58
b)5x+4-3.5x+3=2.511
c)6.8x-1+8.x+1=6.819+821
giúp mk với sáng mai mk đi học rồi
Tìm x
a, (x-2)^5=(x-2)^3
b,(x-3)^3=(x-3)^2 c,11.6^x-1+2.6^x+1 =11.6^11+2.6^13
d, 6.8^x-1+8^x-1=6.8^19+8^21
a: =>(x-2)^3*[(x-2)^2-1]=0
=>(x-2)(x-3)(x-1)=0
=>\(x\in\left\{1;2;3\right\}\)
b: =>(x-3)^2*(x-3-1)=0
=>(x-3)(x-4)=0
=>x=3 hoặc x=4
c: =>\(11\cdot\dfrac{6^x}{6}+2\cdot6^x\cdot6=6^{11}\left(11+2\cdot6^2\right)\)
=>6^x(11/6+12)=6^12(11/6+12)
=>x=12
Tìm x thuộc Z, biết:
1) \(3.5^{x+5}+4.5^{x-3}=19.5^{10}\)
2) \(6.8^{x-1}+8^{x+1}=6.8^{19}=8^{21}\)
3) \(5.2^x+3.2^{x+2}=5.2^5+3.2^7\)
Tìm x:a) -5(x-1)+13=2(8-x)-15
b) 3.5x+2+4.5x-3=19.510
c) 6.8x-1+8x+1=821+819.6
1, 5.3\(^x\)=5.3\(^4\) 2, 7.4\(^x\)=7.4\(^3\) 3, 8.7\(^x\)=8.7\(^6\)
4, 2\(^x\)=2.2\(^8\) 5, 6.8\(^{x-1}\)+8\(^{x+1}\)=6.8\(^{19}\)+8\(^{21}\) 6, 4.3\(^{x-2}\)+2.3\(^{x+1}\)=4.3\(^4\)+2.3\(^7\)
7,(3x-4)\(^6\)=(3x-4)\(^2\) (\(\dfrac{1}{2}\)-\(\dfrac{1}{6}\)):3\(^x\)+3\(^{x+2}\)=3\(^{16}\)+3\(^{13}\)
1: \(5\cdot3^x=5\cdot3^4\)
nên \(3^x=3^4\)
hay x=4
2: \(7\cdot4^x=7\cdot4^3\)
nên \(4^x=4^3\)
hay x=3
3: \(8\cdot7^x=8\cdot7^6\)
nên \(7^x=7^6\)
hay x=6
: 5⋅3mũx=5⋅34
nên 3x=34
vậy x=4
2: 7⋅4x=7⋅43
nên 4x=43
vậy x=3
3: 8⋅7x=8⋅7mũ6⋅
nên 7x=76
Tìm số nguyên x, nếu biết:
1)\(4.3^{x-1}+2.3^{x+2}=4.3^6+2.3^9\)
2)\(\frac{5}{3}.8^{x+2}-\frac{3}{5}.8^x=\frac{5}{3}.8^{11}-\frac{3}{5}.8^9\)
3)\(\left(\frac{1}{3}+\frac{1}{6}\right).2^{x+4}-2^x=2^{13}-2^{10}\)
Mấy bn giúp mk nha!!! lm câu nào cg đc hết á, cảm ơn nha!!!!!
:D
a) \(\Leftrightarrow2.\left(\frac{2.3^x}{3}+3^x.3^2\right)=2.3^6\left(2+3^3\right)\)
\(\Leftrightarrow2.\left(\frac{2.3^x+3.3^x.3^2}{3}\right)=2.3^6.29\)
\(\Leftrightarrow2.\left[\frac{3^x.\left(2+3.3^2\right)}{3}\right]=2.3^6.19\)
\(\Leftrightarrow2.3^{x-1}.29=2.3^6.29\Leftrightarrow3^{x-1}.29=\frac{2.3^6.29}{2}=3^6.29\Leftrightarrow3^{x-1}=\frac{3^6.29}{29}=3^6\)
\(\Leftrightarrow3^{x-1}=3^6\Leftrightarrow x-1=6\Leftrightarrow x=6+1=7\)
vậy x=7 . Chọn mình nha
mấy bài sao tương tự nếu ko biết thì nhắn tin mình chỉ típ nha
1. Tìm x:a) -5(x-1)+13=2(8-x)-15
b) 3.5x+2+4.5x-3=19.510
c) 6.8x-1+8x+1=821+819.6
2. Rút gọn
(-1/2)3-(3/4)3.(-2)2/ 2.(-1)7+(3/4)2-3/8
3) Cho A=1/4x(x-3). tìm x để
a) A=0
b) A > hoặc= 0
c) A<0