Respuesta :

We want to know which ordered pair is a solution of the system of inequalities shown:

[tex]\begin{cases}x-4y\ge0 \\ x-y<-1\end{cases}[/tex]

For doing so, we will try to solve both inequalities for one variable, in this case, we will use y.

On the first equation:

[tex]\begin{gathered} x-4y\ge0 \\ x\ge4y \\ y\le\frac{x}{4} \end{gathered}[/tex]

On the second equation:

[tex]\begin{gathered} x-y<-1 \\ x+1-y<0 \\ x+1And joining those two results we get:[tex]x+1Now we check each of the ordered pairs, if they hold the condition above:

For (0, 2)

We have that x=0, and y=2. Thus,

[tex]\begin{gathered} x+1=1 \\ \frac{x}{4}=0 \\ \text{And as }2>0,\text{ (0, 2) is NOT a solution of the system.} \end{gathered}[/tex]

For (-3, 8)

In this case, x=-3 and y=8.

[tex]\begin{gathered} x+1=-2 \\ \frac{x}{4}=-\frac{3}{4} \\ \text{As }8>-\frac{3}{4},\text{ this means that (-3, 8) is NOT a solution of the system.} \end{gathered}[/tex]

For (2,5)

In this case, x=2 and y=5.

[tex]\begin{gathered} x+1=3 \\ \frac{x}{4}=\frac{2}{4}=\frac{1}{2} \\ \text{As }5>\frac{1}{2}\text{ this means that (2, 5) is NOT a solution of the system.} \end{gathered}[/tex]

For (-7, -4)

In this case, x=-7 and y=-4.

[tex]\begin{gathered} x+1=-6 \\ \frac{x}{4}=-\frac{7}{4} \\ \text{As }-6<-4\le-\frac{7}{4},\text{ (-7, -4) is a SOLUTION of the system.} \end{gathered}[/tex]

For (6, -1)

We have that x=6 and y=-1.

[tex]\begin{gathered} x+1=7 \\ \frac{x}{4}=\frac{6}{4}=\frac{3}{2} \\ \text{As }7>-1,\text{ (6, -1) is NOT a solution of the system. } \end{gathered}[/tex]

Thus, the ordered pair which is a solution of the system is (-7, -4).