\(y\times y=20\Rightarrow y^2=20\Rightarrow y^2=\left(+_-\sqrt{7}\right)^2\Rightarrow y=+_-\sqrt{7}\)
\(y\times y=20\Rightarrow y^2=20\Rightarrow y^2=\left(+_-\sqrt{7}\right)^2\Rightarrow y=+_-\sqrt{7}\)
tim so tu nhien co hai chu so .Biet rang tong cac chu so bang 6 va neu them vao so don vi thi duoc mot so cung viet bang cac chu so do nhung theo thu tu nguoc lai
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tim so tu nhien x;y biet ;2^x+1*3^y=36^x
Tim so tu nhien a, biet rang a la so nho nhat co hai chu so ma khi chia cho 2,3,5,9 deu co so du la 1
Tim cac so nguyen y sao cho bieu thuc 2377-9y^2-6y la binh phuong mot so tu nhien
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Co hay ko so tu nhien x, y de x2+y va y2+x deu la scp
a)Tim tat ca cac so nguyen duong x, y , z thoa man: \(\frac{x+y\sqrt{2013}}{y+z\sqrt{2013}}\)la so huu ti, dong thoi x2 + y2+ z2 la so nguyen to.
b) Tim so tu nhien x, y thoa man: x(1+x+x2) = y(y-1).