Question

3x + 4y = 5

6x + 7y = 8

Answer 1

\(\left\{{}\begin{matrix}3x+4y=5\\6x+7y=8\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}6x+8y=10\\6x+7y=8\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}y=2\\3x+8=5\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}x=-1\\y=2\end{matrix}\right.\)

Vậy hệ phương trình có nghiệm duy nhất \(\left(x;y\right)=\left(-1;2\right)\)

Answer 2

`{(3x+4y=5),(6x+7y=8):}`

`<=>{(6x+8y=10),(6x+7y=8):}`

`<=>{(y=2),(3x+4y=5):}`

`<=>{(y=2),(3x+4.2=5):}`

`<=>{(x=-1),(y=2):}`

Answer 3

\(\left\{{}\begin{matrix}3x+4y=5\\6x+7y=8\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}6x+8y=10\\6x+7y=8\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}y=2\\3x+4.2=5\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}y=2\\x=-1\end{matrix}\right.\)

Vậy hệ phương trình có nghiệm duy nhất \(\left(x;y\right)=\left(-1;2\right)\)

Answer 4

3X+4Y=5

6X+7Y=8

⇔6X+8Y=10

⇔6X+7Y=8

⇒Y=2

⇒X= -1