a) 2^x.4 = 128 b) x^15 = x c)2^x.2^2^2=2^3^2 d) (x^5)^10=x
2^x.4 = 2^7 =>x=1;x=-1;x=0 2^x.2^4=2^6 x^50=x
x.4 = 7 2^x=2^6:2^4 =>x=1;x=0
x=7/4 2^x=2^2
x=2
a) 2^x.4 = 128 b) x^15 = x c)2^x.2^2^2=2^3^2 d) (x^5)^10=x
2^x.4 = 2^7 =>x=1;x=-1;x=0 2^x.2^4=2^6 x^50=x
x.4 = 7 2^x=2^6:2^4 =>x=1;x=0
x=7/4 2^x=2^2
x=2
tim so tu nhien x biet :((10 x)x 2 5 ) :3 -2 = 7
1)a)Tìm số tu nhiên k dể 31k là so nguyên to
b)tim so tu nhien a co 2 chu so nho hon 32 thoa man 273,2271,1785deu chia cho a du 5
c)tim so tu nhien nho nhat co 4 chu so . biet rang khi chia so do cho cac so 70,210,360 có cùng so dư là 5
2)tim so tu nhien co 3 chu so , biet rang khi chia so do cho 8 thi du 7 , chia cho 31 thi du 15.
3)So hoc sinh khoi 6 cua mot truong trong khoang tu 150 den 200,khi xep hang 12,hang 18,deu thua 10 học sinh.
4)tim so nguyên x , biet :
a)59-(5-x)=24-(16-12^0) ; b)5+3^2./x/=50
c)9^2-/x+1/=/-51/ ; d)157-6.(x-3)=11^2
tim x dua vao quan he uoc boi:
tim so tu nhien x sao cho x-1 la uoc cua 12
tim so tu nhien x sao cho 2x+1 la uoc cua 28
tim so tu nhien x sao cho x+15 la boi cua x+3
tim cac so nguyen x,y sao cho (x+1)(y-2)=3
tim so nguyen x sao cho(x+2).(y-1)=2
tim so nguyen to x vua la uoc cua 275 vua la uoc cua 180
tim so nguyen to x,y biet x+y=12 va UCLL (x:y)=5
tim so tu nhien x,y biet x+y=32 va UCLL (x:y)=8
tim so tu nhien x biet x chia het cho10; xchia het cho12; x chia het cho15 va 100<x<150
tim so x nho nhat khac 0b biet x chia het cho 24 va 30
40 chia het cho x . 56 chia het cho x va x>6
tim 2 so tu nhien x va y biet 1) (2x+1)x(y-3)=10 2) (x+1)x(2y-5)=143 3) (3x-2)x(2y-3)=1 4) (x+1)x(2y-1)=12
a,Tim so tu nhien x, biet: 5^x ×5^x+1×5^x+2=1000...0 (2018 cs 0) ÷2^18
b,CMR voi moi so tu nhien n thi ƯCLN (21n+1,14n+3)=1
tim so tu nhien x , biet:
4 nhan ( 2017- 16 x )=102- 25
b1 tim so tu nhien lon nhat co 3 chu so biet rang chia cho 5; 7 ; 9 thi co so du lan luot la 2 ; 4 ;6
b2 tim x biet
a ) 2x +3 chia het cho x -1
b)3x+5 chia het cho x+1
b3 chung to rang 3n+4 va 4n +5 la 2 so nguyen to cung nhau vs moi so TN
B1:tim cac so nguyenx,y biet:
X,y + 2.x- 3y= 11
B2 tim x biet
A -15.(x+2)+7.(2x-3)=(-5) . (+10)
Giai gap minh nhe
Bai 1: a)Tim so tu nhien a biet 1960va2002 chia cho a cung co so du la 28
b)Tim 2 sop tu nhien a va b , biet :BCNN(a,b)=300;UCLN(a,b)=15 va a+15=b
Bai 2:a)Tong sau la binh phuong so nao ?
S=1+3+5+7+...+199
b) Cho so ab va so ababab
1)chung to ababab la boi cua ab
2)So 3 va 10101 co phai la uoc cua ababab khong , vi sao?
Bai 3
a)Hay viet them dang sau so 664 ba chu so de nhan duoc sdo co 6 chu so chia het cho 5,9,11
b)Tim so nguyen x thuoc Z biet rang :
(x^2-1)(x^2-4)<0
Bai 4 :tim so nguyen x va y biet: xy-x+2y=3