Question

2x - y = 4X -2y = -1​

Answer 1

Respuesta:

$2x-y=4,\:x-2y=-1\quad :\quad x=3,\:y=2$

Explicación paso a paso:

$\begin{bmatrix}2x-y=4\\ x-2y=-1\end{bmatrix}\\\\2x-y = 4 : x = \frac{4 + y}{2} \\2x-y+y=4+y\\2x=4+y\\\frac{2x}{2}=\frac{4}{2}+\frac{y}{2}\\x=\frac{4+y}{2}\\\\\begin{bmatrix}\frac{4+y}{2}-2y=-1\end{bmatrix}\\\begin{bmatrix}\frac{4-3y}{2}=-1\end{bmatrix}$$x=3$

$\frac{2\left(4-3y\right)}{2}=2\left(-1\right)\\4-3y=-2\\4-3y-4=-2-4\\-3y=-6\\\frac{-3y}{-3}=\frac{-6}{-3}\\y=2$

$x=3,\:y=2$