Question

giải HPT bằng phương pháp thế

Answer 1

Sửa đề: \(\left\{{}\begin{matrix}\left(2x-3\right)\left(2y+4\right)=4x\left(y-3\right)+54\\\left(x+1\right)\left(3y-3\right)=3y\left(x+1\right)-12\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}4xy+8x-6y-12=4xy-12x+54\\3xy-3x+3y-3=3xy+3y-12\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}8x-6y-12=-12x+54\\-3x+3y-3=3y-12\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}20x+6y=66\\-3x=-9\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x=3\\6y+20\cdot3=66\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x=3\\6y=6\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x=3\\y=1\end{matrix}\right.\)