Question

Tìm các cặp số nguyên x , y biết:

a) (x - 1 ) ( y + 2 ) = 17

b) x( y - 3 ) = -12

c) xy -3x - y = 0

d) xy + 2x + 2y = -16

Answer 1

\(\left(x-1\right)\left(y+2\right)=17\\\Rightarrow\left[{}\begin{matrix}x-1=17\\y+2=17\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=18\\x=15\end{matrix}\right.\)

vậy...

Answer 2

\(x\left(y-3\right)=-12\\ \Rightarrow\left[{}\begin{matrix}x=-12\\y-3=-12\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-12\\y=-9\end{matrix}\right.\)

vậy...