\(9^{x-1}=9\\ Mà:9^1=9\\ =>9^{x-1}=9^1\\ =>x-1=1\\ =>x=1+1=2\)
Vậy: x=2
\(9^{x-1}=9\)
Vì \(9\ne-1;9\ne0;9\ne1\) nên \(x-1=1\Rightarrow x=2\)
Vậy \(x=2\)
Chúc bạn học tốt!!!
Tim x biet
A, 5/9 + x/-1 = -1/3
B, 1/5 + 2/20 + 121/165 <x< 1/2 + 156/72 + 1/3 ( x thuoc N)
C, x + 5/3 = 1/81
D, x-1/3 + 3x-5/2 + 2x/9 + -5x+3/9 = 210/420
Tìm X
a) (7-x)-(25+7)=9-25
b) x-(1-x)-5+(-1+x)
c) -12+(x-9)=0
d) 11+(15-x)=1
a) 5/7 - x = -9/21
b) - x - 1/9 = -2/45
c) | x + 5/6 | = 11/24
3x-15 = 12 5x-1 -12 =13 3x-2.9 = 81 3x+1: 9 = 3 2.x3 = 16 75 : x2 = 3
Tìm n
1/2 x 2^n + 4 x 2^n = 9 x 5^n
Tính hợp lý
a) A= ( 2^8 + 3^8) : ( 2^5 x 2^3)
b) B = ( 2^17 + 17^2) x (9^15 - 15^9) x (4^2 - 2^4)
Tìm x biet
A, 2/3 × x - 4/7 = 1/8
B, 2/7 - 8/9 × x = 2/3
C, 4/7 + 5/9 : x = 1/5
Trong bài phép chia phân số (Chương trình VNEN)
Tìm x
a ) 4/9.x = 1/9
b) 7/18 . x - 2/3 = 5/18
c) x:-1/12 = 7/12
d) 4/9- 7/8.x = -2/3
e) -5/14 : x = -3/10
g) 1/6 + -5/7 : x = -7/18
Tìm x thuộc Z:
1) -5x - (-3) = 13
2) 15 - ( x - 7) = -21
3) 45 - ( x - 9) = -35
4) | x - 2 | = 3
5) | x - 3| - 7 = 13
6) 72 - 3 . | x + 1 | = 9
7) 17 - ( 43 - | x | ) = 45
8) 3| x - 1| - 5 = 7
9) -12( x - 5) + 7( 3 -x) = 5
10) (x - 2) . ( x + 4 ) = 0
tim x, y biet
x/49=-3/7
b, x-2/12=2/3
c,x-1/9=x+3=15
d,3/x=9/35=-36/84
