Question

Tìm cặp số nguyên x,y biết: (2x-1).(y-4)=-13

Answer 1

\(\Rightarrow\left(2x-1\right)\left(y-4\right)=-13\cdot1=-1\cdot13\)

Ta có bảng:

\(2x-1\)	-13	1	-1	13
\(y-4\)	1	-13	13	-1
\(x\)	-6	1	0	7
\(y\)	5	-9	17	3

 

Answer 2

Cũng tương tự bài lúc nãy ấy

Answer 3

(2x-1).(y-4)=13

⇔\(2xy-8x-y+4=13\)

⇔\((2xy-y)-(8x-4)=13\)

⇔\(y(2x-1)-4(2x-1)=13\)

⇔\((y-4)(2x-1)=13\)

⇔\((y-4)(2x-1)-13=0\)

⇔\(\left\{{}\begin{matrix}y-4=0\\2x-1=0\end{matrix}\right.\)⇔\(\left\{{}\begin{matrix}y=4\\2x=1\end{matrix}\right.\)⇔\(\left\{{}\begin{matrix}y=4\\x=0,5\end{matrix}\right.\)