Question

tìm x và y cho biết (X-3).(X+Y)=-7

Answer 1

\(\left(x-3\right).\left(x+y\right)=-7\)

\(\Rightarrow x-3=-7\Rightarrow x=-4\)

 \(\Rightarrow\left(-4-3\right).\left(-4+y\right)=-7\)

\(=-7.\left(-4+y\right)=-7\)

\(\left(-4\right)+y=\left(-7\right):\left(-7\right)\)

\(\left(-4\right)+y=1\Rightarrow y=5\)

Vậy : \(x=-4\) ; \(y=5\)