Tim x thuoc n
a,x^2006=x
b,3^x+1+3^x=108
c,x^207=x
d,(1+3x)^4=256
Tim n thuoc N.
a)16<4n<256 ;(x+1)4=81
a) 16<4n<256
<=> 42<4n<44 => n=3
(x+1)4=81=34
=>x+1=3
=>x=2
tim STN x biet
a, 21 thuoc B(x-3)
b, 1-x thuoc U(17)
c, 2x+3 thuoc B(2x-1)
d, x+1 thuoc U(x mu 2+x+3)
e, 3x+1:11-2x
a: \(\Leftrightarrow x-3\inƯ\left(21\right)\)
\(\Leftrightarrow x-3\in\left\{-3;-1;1;3;7;21\right\}\)
hay \(x\in\left\{0;2;4;6;10;24\right\}\)
b: \(\Leftrightarrow x-1\in\left\{1;-1;17\right\}\)
hay \(x\in\left\{2;0;18\right\}\)
c: \(\Leftrightarrow2x-1+4⋮2x-1\)
\(\Leftrightarrow2x-1\in\left\{1;-1\right\}\)
hay \(x\in\left\{1;0\right\}\)
d: \(\Leftrightarrow x^2+x+3⋮x+1\)
\(\Leftrightarrow x+1\inƯ\left(3\right)\)
\(\Leftrightarrow x+1\in\left\{1;3\right\}\)
hay \(x\in\left\{0;2\right\}\)
bai 1:tim x
a) (x+1/5)2+17/25=26/25
b)-1va 5/27-(3x-7/9)3=-24/27
bai 2:cho A=n+2/n-5 (n thuoc Z ;n khac 5).Tim x de A thuoc Z
1a. x=-0,8
b)-1va 5/27-(3x-7/9)3=-24/27 mik ko hỉu đề
2.n= 6
cho p=( 3/x^4-x^3+x-1)-(1/x^4+x^3-x-1)-(4/x^5-x^4+x^3-x^2+x). cmr p la so duong voi moi x thuoc moi mien xd cua p
tim x thuoc n: 34.3^n :9=37
tim x thuoc n: 9<3^n<27
Tim chu so tan cung cua 360
hãy so sánh a=1+3+3^2+3^3+3^4+35+36 và B=37-1
a/ 34 . 3n : 9 = 34 => 34 . 3n = 34 x 9 => 34 . 3n = 306 => 3n = 306 : 34 => 3n = 9 => n = 2
b/ 9 < 3n < 27 => 32 < 3n < 33 => 2 < n < 3
Mà: n thuộc N => n không tồn tại
c/ Chữ số tận cùng của 360 là 0
d/ Ta có: A = 1 + 3 + 32 + 33 + 34 + 35 + 36
=> 3A = 3 + 32 + 33 + 34 + 35 + 36 + 37
=> 3A - A = 2A = (3 + 32 + 33 + 34 + 35 + 36 + 37) - (1 + 3 + 32 + 33 + 34 + 35 + 36 ) = 3 + 32 + 33 + 34 + 35 + 36 + 37 - 1 - 3 - 32 - 33 - 34 - 35 - 36
=> 2A = 37 - 1 => A = (37 - 1) : 2 < 37 - 1 = B
=> A < B
Bai 1:
a) Cho A = 963 + 351 + x voi x thuoc N . Tim dieu kien cua x de A chia het cho 9 , de A khong chia hat cho 9
b) Cho B = 10 + 25 + x + 45 voi x thuoc N . Tim dieu kien cua x De B chia het cho 5 , B khong chia het cho 5
Bai 2 : Tim x thuoc N biet :
a) 1 + 2 + 3 + ..... + n = 325
b) 1 + 3 + 5 +... + ( 2n+1) = 144
c) 2 + 4 + 6 + ... + 2n = 756
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
a: -x+5/9=-1/3
nên x=5/9+1/3=5/9+3/9=8/9
b: \(\Leftrightarrow\dfrac{1}{5}+\dfrac{1}{10}+\dfrac{11}{15}< x< \dfrac{1}{2}+\dfrac{13}{12}+\dfrac{1}{3}\)
=>31/30<x<23/12
mà x là số nguyên
nên \(x\in\varnothing\)
c: x+5/3=1/81
nên x=1/81-135/81=-134/81
a x e x
b x f x
c x x
2
3
2 1 1 1 17 26
3 2 10 5 25 25
4 2 5 7 24
2 50 51 1 3
5 3 27 9 27
1 2
2 0
2 3 ) :
) ) ,
g x
d x h x x
3 1
1 4
7 28
17 3 7 2 7
2 0 5
2 4 4 3 12
1.Tìm x thuoc N de
x^2+2x-5 chia het cho x
2.tim x thuoc N de
x^2+x=132
3.tim x,y de
x^2+xy=5
4.tim a thuoc N de
a)a+10 chia het cho a-1
b)3a-6 chia hết cho 3a
Giúp mink với mink cần giúp rồi mink tick cho nhé
1.x=1;5
2.x=11
3.x=1;y=4
4.a)a=2;12 b)a=1;2
nho h cho minh nha