tim x dua vao quan he uoc boi:tim so tu nhien x sao cho x-1 la uoc cua 12tim so tu nhien x sao cho 2x+1 la uoc cua 28tim so tu nhien x sao cho x+15 la boi cua x+3tim cac so nguyen x,y sao cho (x+1)(y-2)=3tim so nguyen x sao cho(x+2).(y-1)=2tim so nguyen to x vua la uoc cua 275 vua la uoc cua 180tim so nguyen to x,y biet x+y=12 va UCLL (x:y)=5tim so tu nhien x,y biet x+y=32 va UCLL (x:y)=8tim so tu nhien x biet x chia het cho10; xchia het cho12; x chia het cho15 va 100<x<150tim so x nho nhat khac 0b...
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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
1: Vì x^2 >=0 với mọi x ; (y- 1/10)^4 >=0 với mọi y
==> x^2 + (y- 1/10)^4 >= 0.
Do đó dấu = xảy ra tức là x^2 + (y- 1/10)^4 =0 <=> x^2 =0 và (y- 1/10)^4 =0 <=> x=0; y=1/10
bài 2 kiểu tương tự nha
(x - 1 )^4sẽ \(0\le\left(x-1\right)^4\)
(y+2)^100 sẽ \(0\le\left(y+2\right)^{100}\)
đến đó bn làm nhé
a) Vì \(x^2\ge0\forall x\)
\(\left(y-\dfrac{1}{10}\right)^4\ge0\forall y\)
\(\Rightarrow x^2+\left(y-\dfrac{1}{10}\right)^4\ge0\forall x,y\)
Dấu "=" xảy ra \(\Leftrightarrow x^2=0;y-\dfrac{1}{10}=0\)
\(\Rightarrow x=0;y=\dfrac{1}{10}\)
b) Vì \(\left(x-1\right)^4\ge0\forall x\)
\(\left(y+2\right)^{100}>0\forall y\)
\(\Rightarrow\left(x-1\right)^4+\left(y+2\right)^{100}\ge0\forall x,y\)
Dấu "=" xảy ra \(\Leftrightarrow x-1=0;y+2=0\)
\(\Rightarrow x=1;y=-2\)