1/ E=[3.4.216] / [ 11*213.411-169]
2/ tim X
1+3+5+7+....+X=1600 [ X la so le ]
(4x + 5 ) : 3 - 121 : 11 = 4
1 + 3 + 5 + ... + x = 1600 (x la mot so tu nhien le)
2x + 2x+3 =144
( x - 5)4 = ( x - 5)6
(4x+5):3-121:11=4
(4x+5):3-11=4
(4x+5):3=15
4x+5=45
4x=40
x=10.
1+3+5+...+x=1600
Gọi x=2k+1
Ta có 1+3+...+x=1600
1+3+..+2k+1=1600
(2k+2)[(2k+1-1)/2+1]/2=1600
(2k+2)(k+1)=3200
2(k+1)(k+1)=3200
(k+1)^2=1600
=>k+1=40
k=39. Vậy x=2k+1=2.39+1=79.
2^x+2^x+3=144
2^x(1+2^3)=144
2^x.9=144
2^x=16
2^x=2^4
=>x=4
(x-5)^4=(x-5)^6
(x-5)^6-(x-5)^4=0
(x-5)^4[(x-5)^2-1]=0
(x-5)^4=0, (x-5)^2-1=0
x-5=0, (x-5)^2=1
x=5, x-5=1, x-5=-1
x=5, x=6, x=4.
tim x la so tu nhien
1+3+5+....+x=3200 (x la so le)
(x+1)+(x+2)+(x+3)+....+(x+100)=5750
mik dag can gap
(x+1)+(x+2)+(x+3)+......+(x+100)=5750=(x+x+x)+(1+2+3+.....+100)=5750 =100x+(1+100)×100:2=5750 =100x+101×50=5750 =100x+5050=5750 =100x=5750-5050 =100x=700 x=700:100 x=7
tim so tu nhien x de cac so sau la so nguyen to
a ,2 .x
b , 7 .x
c , 3 . [ x-6]
d,5-x
e,7-x
g,11-x
f, 11 .[x-15]
h,2 mu3 .b +3 mu 2 .b
a. x=1
b. x=1
c. x=7
d. x=0 ; x=2; x=3
e.x=0;x=2;x=4;x=5
g.x=0;x=4;x=2;x=6;x=8;x=9
f. x=16
h.b=1
a)1/5*7+1/7*9+1/9*11+...+2005*2011+1/X=1/5*0,5
b)1-(11 1/2[hon so]+X-10,1)/8 2/5[hon so]=0
c)1-(5 2/9[hon so]+X7 7/18[hon so])/2 1/6[hon so]=0
ban oi bai nay lam kieu j giup minh voi
1 nto X co 3 dvi A, B, C lan luot chiem ti le la 79%, 10%, 11%. Tong so khoi cua 3 dvi la 75, ntktb cua X la 24,32. Mat khac, so n cua B nhieu hon cua A la 1
a) tim so khoi
b) biet trong A co so p=n, tim X
Giai giup mik, cam on
a,cho x va y la hai dl ti le thuan bit khi x=2 thi y =7 .tim he so ti le cua y doi voi x
b, tinh gtri cua y khi x =5 tinh gtri cua x khi x= 1/2
tim x thuoc N
a,\(5x+1⋮7\) va x la STN be nhat co 3 chu so
b,\(\left(3x+2\right)⋮11\) va \(100\le x\le2017\)
a) Vì 1 : 7 dư 1 và 5x + 1 \(⋮\) 7 nên 5x : 7 dư 6
Vì x là số tự nhiên bé nhất có 3 chữ số khi thay vào 5x thì 5x : 7 dư 6 nên x = 102
Vậy, x = 102
tinh hop li
1+3+5+..........+x=1600(so le)
1. Tim x la so tu nhien be nhat sao cho :
( x - 8,25 * 4 ) : ( x - 8,25 * 4 ) = 1
2. Tim so a , biet a la tu nhien le nho hon 100 va trong phep chia a cho b duoc thuong la 3 du 22
1 . ko chắc
( x - 33 ) : ( x - 33 ) = 1
=> x - 33 = 1
x = 33 + 1
x + 34