Tim x biet
(X+1)×(x+2)<0 x-2/3x+2 <0
(-3+3/x -1/3) ÷ (1+2/3+2/5)=-5/4
a, Cho F(x) = a x+b . Tim a,b biet f(0) = 3 va F(2) =-1
b, Cho F(x) =a x+ b. Tim a,b biet F(1) = -1 va F(-2) = 8
c, Cho F(x) =a x +b .tim a,b biet F(0) = 1 va F(-2) = -9
tim x nguyen biet /x-1/^2+(x-1)^2=2015./x-1/
tim x
giup dum
a, Tim so tu nhien x, y biet rang 4<9/x<12/y<18
b, Tim so nguyen x, y biet rang x/2 - 2/y = 1/2
Lam cach nao de ra duoc ket qua nhu vay ha ban?
1 tim MAX cua (x+z)(y+t) biet x^2+y^2+z^2+t^2=1
2 tim MAX cua (x+z)(y+t) biet x^2+y^2+2z^2+2t^2=1
tim x biet x(x-2)(x-1)(x+1)=24
ta thấy x(x-2)(x-1)(x+1) là các số tự nhiên liên tiếp
mà 24 = 1 x2 x3 x4
1 x 2 x 3 x 4 = (x-2)(x-1)x(x+1)
x = 3
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 x biet : |x^2+x|+|(x+1)*(x-2)|=0
Ta co: |x2+x|+|(x+1).(x-2)|=0
Ma |x2+x|>=0,moi x thuoc R
|(x+1).(x-2)|>=0,moi x thuoc R
=>|x2+x|=0
|(x+1).(x-2)|=0
<=>x=-1
Vay x=-1.
tim x biet x+1=1/2
Tim x biet : 20 . 2^x + 1 = 10.4^2 + 1
Tim x : ( 4-x:2)^3 - 1 = 2 . (2^3 - 5 : 2^0 )
20 . 2^x + 1 = 10.4^2 + 1
20 . 2^x + 1 = 10 . 16 + 1
20 . 2^x + 1 = 161
20 . 2^x = 161 - 1
20 . 2^x = 160
2^x = 8
2^x = 2^3
=> x = 3
( 4 - x : 2 )^3 - 1 = 2 . ( 2^3 - 5 : 2^0 )
( 4 - x : 2 )^3 - 1 = 2 . ( 8 - 5 : 1 )
( 4 - x : 2 )^3 - 1 = 2 . 3
( 4 - x : 2 )^3 - 1 = 6
( 4 - x : 2 )^3 = 7
=> ko tìm đc x
tim x biet x+34 la boi cua x+1 tim x biet 2x+1 la uoc cua x+82