a)\(5^x+5^{x+1}=650\)
b)\(3^{x-1}+5\times3^{x-1}=162\)
Tìm x:
a, \(\left|x+1\right|+\left|-13\right|=26\\ \)
\(b,\)\(3^{x+2}+3^x=250\)
\(c,\)\(3^{x-1}+5\times3^{x-1}=162\)
\(d,\)\(5^x+5^{x+2}=650\)
a) \(\left|x+1\right|+\left|-13\right|=26\)
\(\left|x+1\right|+13=26\)
\(\left|x+1\right|=26-13\)
\(\left|x+1\right|=13\)
\(\Rightarrow\orbr{\begin{cases}x+1=13\\x+1=-13\end{cases}}\Rightarrow\orbr{\begin{cases}x=12\\x=-14\end{cases}}\)
vậy ........
b) \(3^{x+2}+3^x=250\)
\(3^x.3^2+3^x=250\)
\(3^x.\left(3^2+1\right)=250\)
\(3^x.10=250\)
\(3^x=25\)
\(\Rightarrow x\in\varnothing\)
Những câu sau tương tự
Tìm x biết:
a) 5x+5x+2=650
b)3x-1+5 x 3x-1 = 162
a) 5X+5X+2=650
=>5X.1+5X.52=650
=>5X.(1+52)=650
=>5X.26=650
=>5x=650:26
=>5X=25
=>5X=52
=>X=2
b) 3X-1+5.3X-1=162
=>3X-1.1+5.3X-1=162
=>3X-1.(1+5)=162
=>3X-1.6=162
=>3X-1=162:6
=>3X-1=27
=>3X-1=33
=>3X=33+1
=>3X=34
=>X=4
=> \(5^x+5^x.5^2=650\)
\(5^x\left(1+5^2\right)=650\Leftrightarrow5^x.26=650\)
\(\Leftrightarrow5^x=25;x=2\)
a) 5x + 5x+2 = 650
b) 3x-1 + 5.3x-1 = 162
a) 5^x + 5^x+2 = 650
<=> 5^x. (1+5^2)= 650
<=> 5^x. 26= 650
<=> 5^x= 25
=> x= 2
b) 3^x-1 + 5.3^x-1 = 162
<=> 3^x-1. (1+5)= 162
<=> 3^x+1. 6= 162
<=> 3^x+1= 27
=> x+1= 3
=> x= 2
a)\(5^x+5^{x+2}=650\)
b)\(3^{x-1}+5.3^{x-1}=162\)
a, 5x+5x+2=650
<=>5x+5x.52=650
<=>5x.(1+52)=650
<=>5x.26=650
=>5x=650:26
=>5x=25=52
=>x=2
b, 3x-1+5.3x-1=162
<=>3x-1.(5+1)=162
<=>3x-1.6=162
=>3x-1=162:6
=>3x-1=27=33
=>x-1=3
=>x=3+1
=>x=4
Chúc bạn học giỏi nha!!!
K cho mik với nhé Nguyễn Công Đạt
\(5^x+5^{x+2}=650\)
\(\Rightarrow5^x+5^{x+2}=625+25\)
\(\Rightarrow5^x+5^{x+2}=5^4+5^2\)
\(\Rightarrow x+x+2=4+2\)
\(\Rightarrow2x+2=6\)
\(\Rightarrow2x=4\)
\(\Rightarrow x=2\)
Các bạn ơi ,giúp mình với
Bài 1:Rút gọn
a)\(\frac{2^{19}\times27^3+15\times4^9\times9^4}{6^9\times2^{10}+12^{10}}\)
b)\(\frac{\left(\frac{-1}{2}\right)^3-\left(\frac{3}{4}\right)^3\times\left(-2\right)^2}{2\times\left(-1\right)^5+\left(\frac{3}{4}\right)^2-\frac{3}{8}}\)
c)\(\frac{45\times9^4-2\times6^4}{2^{19}\times3^8+6^8\times20}\)
Bài 2:Tìm x
a)\(5^x+5^{x+2}=650\)
b)\(3^{x-1}+5\times3=162\)
Tìm x
3^x-1 + 5.3^x-1 = 162
5^x + 5^x+2 = 650
3x-1+5.3x-1=162
=>3x-1.(1+5)=162
=>3x-1.6=162=>3x-1=162:6=27=33
=>x-1=3=>x=4
5x+5x+2=650
=>5x+5x.52=650
=>5x.(1+25)=650
=>5x.26=650=>5x=650:26=25=52
=>x=2
a) (2x-1)^3=27
b) (2x-1)^4=81
c) (x-2)^5=-32
d) (3x-1)^4=(3x-1)^6
đ) 5^x +5^x+2=650
g) 3^x-1 +5.3^x-1=162
a) (2x-1)3 = 27
(2x-1)3 = 93
2x-1 = 9
2x = 9+1
2x = 10
x = 10:5
x = 2
Vậy x = 2
b) (2x-1)4 = 81
(2x-1)4 = (\(\pm\)34)
2x-1 = \(\pm\)3
Trường hợp 1:
2x-1 = 3
2x = 3+1
2x = 4
x = 4:2
x = 2
Trường hợp 2:
2x-1 = -3
2x = -3+1
2x = -2
x = -2:2
x = -1
Vậy x \(\in[_{ }2;-1]\)
Vì không tìm thấy ngoặc nhọn nên mình dùng tạm ngoặc vuông nhé
À phần b) bạn sửa dòng (2x-1)4 = (\(\pm\)34) thành (2x-1)4 = (\(\pm\)3)4 nhé
Mình vừa viết nhầm
tìm số tự nhiên x biết rằng
a. 5x + 5x+2 = 650
b. 3x-1 + 5.3x-1 =162
a) \(5^x+5^{x+2}=650\)
\(5^x+5^x.5^2=650\)
\(5^x.\left(1+5^2\right)=650\)
\(5^x.26=650\)
\(5^x=25\)
\(5^x=5^2\)
\(\Rightarrow x=2\)
Vậy x = 2
b) \(3^{x-1}+5.3^{x-1}=162\)
\(3^{x-1}.\left(1+5\right)=162\)
\(3^{x-1}.6=162\)
\(3^{x-1}=162:6\)
\(3^{x-1}=27\)
\(3^{x-1}=3^3\)
\(\Rightarrow x-1=3\)
\(x=3+1\)
\(x=4\)
Vậy x = 4
a) 5x+5x + 2 = 650
=> 5x+ 5x.52 = 650
=> 5x(1+ 52) = 650
=> 5x.26 = 650
=> 5x = 650:26
=> 5x = 25
=> 5x = 52
=> x = 2
Vậy x = 2
b) 3x-1 + 5.3x-1 = 162
=> 3x-1(1+5) = 162
=> 3x-1. 6 = 162
=> 3x-1 = 162
=> x ko có giá trị
Vậy x ko tìm đc giá trị thỏa mãn đề bài.
5^x + 5^x+2=650
3^x-1 + 5×3^x-1=162
(2x-1)^6=(1-2x)^8
a)5x+5x+2=650
2*5x+2=650
2(5x+1)=650
5x+1=650/2
5x+1=325
5x=325-1
5x=324
=>x \(\in\phi\)
b)3x-1+5*3x-1=162
3x-1(1+5)=162
3x-1=162/6
3x-1=27=33
=>x-1=3
x=3+1
x=4
c)(2x-1)6=(1-2x)8
(2x-1)6=(-2x-1)8=(2x-1)8=(2x-1)6*(2x-1)2
=>(2x-1)2=1
2x-1=1
2x=1+1
2x=2
x=2/2
x=1
*)2x-1=0
2x=0+1
2x=1
x=1/2