Question

1.Tìm các số nguyên x,y bt:

a, (x+1)×(y+3)=5

b, x^2 + 4xy=11

c, x^2 + xy + y =22

Answer 1

a,\(\left(x+1\right)\left(y+3\right)=5\)

Ta có:5=5.1=1.5

\(\Leftrightarrow\left[{}\begin{matrix}x+1=5\\x+1=1\\y+3=5\\y+3=1\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=0\\y=2\\y=-2\end{matrix}\right.\)

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