Tìm x biết:
c )\(\left(8x-1\right)^{2n+1}=5^{2n+1}\)
Tìm x biết:
\(\left(x-7\right)^{x+1}-\left(x-7\right)^{x+11}=0\)
\(\left(8x-1\right)^{2n+1}=5^{2n+1}\)
(x-7)x+1-(x-7)x+11=0
=>x-7=0
=>x=7
(8x-1)2n+1=52n+1
=>8x-1=5
=>8x=6
=>x=3/4
Tick Đúng Nha
Tìm n , biết
\(\left(8x-1\right)^{2n+1}=5^{2n+1}\)
\(\left(8x-1\right)^{2n+1}=5^{2n+1}\)
\(\Leftrightarrow8x-1=5\)
\(\Leftrightarrow x=\frac{3}{4}\)
\(\left(8x-1\right)^{2n+1}=5^{2n+1}\)
\(\Rightarrow8x-1=5\)
\(\Rightarrow8x=6\)
\(\Rightarrow x=\frac{3}{4}\)
Vậy \(x=\frac{3}{4}\)
\( \left(8x-1\right)^{2n-1}:5=5^{2n}\)
\(\left(x-\dfrac{2}{9}\right)^3=\left(\dfrac{2}{3}\right)^6\)
\(\text{đề bài là tìm x nhá mn}\)
b) \(\left(x-\dfrac{2}{9}\right)^3=\left(\dfrac{2}{3}\right)^6\)
\(\Rightarrow\left(x-\dfrac{2}{9}\right)^3=\left[\left(\dfrac{2}{3}\right)^2\right]^3=\left(\dfrac{4}{9}\right)^3\)
\(\Rightarrow x-\dfrac{2}{9}=\dfrac{4}{9}\)
\(\Rightarrow x=\dfrac{2}{3}\)
Thui làm hộ cho:
\(\left(8x-1\right)^{2n-1}:5=5^{2n}\)
\(\left(8x-1\right)^{2n-1}=5^{2n}.5\)
mà àm cho khỏi nhân 5 hay chia 5 vậy
bài 1 : tìm x: \(x+\left(-\frac{31}{12}\right)^2=\left(\frac{49}{12}\right)^2-x=y^2\)
bài 2: tìm x : \(\left(8x-1\right)^{2n+1}=5^{2n+1}\)(n thuộc N)
Tìm x biết: \(\left(8x-1\right)^{2n+1}=5^{2n+1}\)
\(\left(8x-1\right)^{2n+1}=5^{2n+1}\)
\(8x-1=5\)
\(8x=6\)
\(x=\dfrac{3}{4}\)
=.= hok tốt!!
Làm tính nhân: a. \(\left(3x^{2m-1}-\dfrac{3}{7}y^{3n-5}+x^{2m}y^{3m}-3y^2\right)8x^{3-2m}y^{6-3n}\)
b.\(\left(2x^{2n}+3x^{2n-1}\right)\left(x^{1-2n}-3x^{2-2n}\right)\)
a: \(=24x^{2m-1+3-2m}y^{6-3m}-\dfrac{24}{7}y^{3n-7+6-3n}\cdot x^{3-2m}+8x^{3-2m+2m}\cdot y^{6-3n+3m}-24x^{3-2m}y^{6-2n+2}\)
\(=24x^2y^{6-3m}-\dfrac{24}{7}x^{3-2m}\cdot y^{-1}+8x^3y^{-3n+3m+6}-24x^{3-2m}y^{-2n+8}\)
b: \(=2x^{2n+1-2n}-6x^{2n+2-2n}+3x^{2n-1+1-2n}-9x^{2n-1+2-2n}\)
\(=2x-6x^2+3-9x\)
\(=-6x^2-7x+3\)
Bài 1: Thực hiện phép tính:
A = \(\left(2x^{2n}+3x^{2n-1}\right)\left(x^{1-2n}-3x^{2-2n}\right)\)
B = \(\left(3x^{2m-1}-\frac{3}{7}y^{3n-5}+x^{2m}y^{3n}-3y^2\right).8x^{3-2m}y^{6-3n}\)
Tim x biet : \(\left(8x-1\right)^{2n+1}=5^{2n+1}\)
nếu n E N thì 2n+1 là số lẻ lúc đó ta có:
(8x-1)2n+1 = 52n+1
<=> 8x - 1 = 5
<=> 8n = 6
<=> n = 6/8 = 3/4
Giải pt
\(x^{5^{n+1}}-2\dfrac{4n}{n-2^{n+5^2}}+\left(8x^{2n+1}\right)=0\)
Lớp 5 đã học giải pt rồi á em?