tìm x
a,5x.(53)2=625
b,(5.x+1)2=36/49
bài 1 :tìm x,y biết
a) (5x+1)=\(\dfrac{36}{49}\) b) (x-2/9) = (2/3) c)(8x-1) 2x+1= 5^2 x+1
d) (x-3,5)^x+(y - 1/10)^4=0
`(5x+1)=36/49`
`<=> 5x = 36/49-1`
`<=> 5x = -13/49`.
`<=> x = -13/245.`
Vậy `x = -13/245`.
`b, x-2/9 = 2/3`.
`<=> x = 2/3 + 2/9`
`<=> x = 8/9`.
Vậy `x = 8/9`.
c: (8x-1)^(2x+1)=5^(2x+1)
=>8x-1=5
=>8x=6
=>x=3/4
d: Sửa đề: (x-3,5)^2+(y-1/10)^4=0
=>x-3,5=0 và y-0,1=0
=>x=3,5 và y=0,1
Tìm x, biết:
a) ( 5x+1)^2+36/49
b) (x-2/9)^3=(2/3)^6
c) (8x-1)^2n+1=5^2n+1
tìm x, biết:
(5x+1)^2=36/49
\(\left(5x+1\right)^2=\frac{36}{49}\)
\(\left(5x+1\right)^2=\left(\frac{6}{9}\right)^2\)
\(5x+1=\frac{6}{9}\)
\(5x=\frac{6}{9}-1\)
\(x=\frac{-1}{3}:5=\frac{-1}{3}.\frac{1}{5}=\frac{-1}{15}\)
tìm x biết:
a/ 5x .(53)2 =625
b/ (5x+1)2 = 36/49
Tìm x,y: (5x+1)^2=36/49=(2y-1)^3
(x-2/9)^3=(2/3)^6=(y/3)^2
(8x-1)^2y+1=5^2y+1 (với y thuộc N)
tìm x biết: (5x+1)2 = 36/49
\(\left(5x+1\right)^2=\frac{36}{49}\)
(+) TH 1: 5x + 1 = 6/7
5x = 6/7 - 1
5x = -1/7
x = -1/7 : 5
x = -1 /35
(+) TH2 : 5x + 1 = - 6/7
5x = -6/7 - 1
5x = -13/7
x =-13/7 : 5
x = -13/35
\(5x-9=5+3x;2^3+0,5x=1,5;\left(5x+1\right)^2=\dfrac{36}{49};\left(\dfrac{-3}{81}\right)^x=-27;2^{x-1}=16\)
Tìm x biết:
(5x + 1)2 = 36/49
( 5x + 1 )2 = 36/49
<=> ( 5x + 1 )2 = ( ±6/7 )2
<=> 5x + 1 = 6/7 hoặc 5x + 1 = -6/7
<=> x = -1/35 hoặc x = -13/35
\(\left(5x+1\right)^2=\frac{36}{49}\)
\(\Rightarrow\orbr{\begin{cases}5x+1=\frac{6}{7}\\5x+1=\frac{-6}{7}\end{cases}}\)\(\)
\(\Rightarrow\orbr{\begin{cases}5x=\frac{-1}{7}\\5x=\frac{-13}{7}\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{-1}{35}\\x=\frac{-13}{35}\end{cases}}\)
\(\left(5x+1\right)=\pm\sqrt{\frac{36}{49}}=\pm\frac{6}{7}\)
\(\orbr{\begin{cases}5x+1=\frac{6}{7}\\5x+1=-\frac{6}{7}\end{cases}}\)
\(\orbr{\begin{cases}5x=\frac{-1}{7}\\5x=\frac{-13}{7}\end{cases}}\)
\(\orbr{\begin{cases}x=\frac{-1}{35}\\x=\frac{-13}{35}\end{cases}}\)
Tìm x biết
(-3/4)^3x -1= 256/81
(5x+1) ^2 =36/49
(X-2/9)^3= (2/6)^6
(8x -1)^2n+1 = 5^2n +1
Tìm x, biết:
a) 5x.(53)2=625
b) (5x+1)2=36/49
c) (8x-1)2n+1=52n=1 (n thuộc N)
\(5^x.\left(5^3\right)^2=625\)
\(\Rightarrow5^x.5^6=5^4\)
\(\Rightarrow5^x=5^4:5^6\)
\(\Rightarrow5^x=\frac{1}{25}\)
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