so xcac cap xy thoa man 4y^2-3+5-2x=2013
Tim tat cac cac cap so nguyen x,y thoa man a) x^2+5xy+4y^2
b)xy-2x+3y-1
Tim tat cac cac cap so nguyen x,y thoa man a) x^2+5xy+4y^2
b)xy-2x+3y-1
Tim tat cac cac cap so nguyen x,y thoa man a) x^2+5xy+4y^2
b)xy-2x+3y-1
so cap so (x;y) thoa man (2x+3)(4y+6)=111
\(\left(2x+3\right)\left(4y+6\right)=111\)
\(\Rightarrow\)111 chia hết cho \(\left(2x+3\right);\left(4y+6\right)\)
Hay \(\left(2x+3\right);\left(4y+6\right)\inƯ\left(111\right)\)
Mặt khác \(4y+6\) là số chẵn mà 111 không có ước chẵn.
\(\Rightarrow\)Không có cặp số (x; y) thỏa mãn.
Tìm cap so tu nhien (x;y) thoa man xy +2x+5y=14
tim cac cap so nguyen x , y thoa man : 2 . ( xy - 3 ) = x
\(2\left(xy-3\right)=x\)
\(\Leftrightarrow2xy-6=x\)
\(\Leftrightarrow2xy-x=0+6\)
\(\Leftrightarrow x\left(2y-1\right)=6\)
\(\Rightarrow x\inƯ\left(6\right)=\left\{\pm1;\pm2;\pm3;\pm6\right\}\)
\(\Rightarrow y\in\left\{....\right\}\)
so cap xy thoa man x^2+y^2=13
so cap (x,y) nguyen thoa man (y+1)(xy-1) =3
tim cap so nguyen (x,y) thoa man: x+y+xy=2