Solve the following system of inequalities graphically:

    \[x+y\ge 4,2x-y<0\]

Solve the following system of inequalities graphically:

    \[x+y\ge 4,2x-y<0\]

Solution:

The given inequalities are

    \[x+y\ge 4,2x-y<0\]

For

    \[x+y\ge 4\]

Let us put the value of

    \[x=0\]

and

    \[y=0\]

in equation one by one, we get

    \[y=4\]

and

    \[x=4\]

Therefore, we got points as

    \[(0,4)\]

and

    \[(4,0)\]

Now check for the origin

    \[(0,0)\]

We got

    \[0\ge 4\]

,which is not true.

We can say that the origin would not lie in the solution area. The required region would be on the right of line`s graph.

Now for

    \[2x-y<0\]

Let us put the value of

    \[x=0\]

and

    \[y=0\]

in equation one by one, we get

    \[y=0\]

and

    \[x=0\]

Let us take

    \[x=1\]

we get

    \[y=2\]

Therefore, the points for the given inequality are

    \[(0,0)\]

and

    \[(1,2)\]

As we can see that the origin lies on the given equation

Now we will check for

    \[(4,0)\]

point to check which side of the line`s graph will be included in the solution.

We get

    \[8<0\]

which is not true

Therefore, the required region would be on the left side of the line

    \[2x-y<0\]

In the below graph the shaded region is the required solution of the inequalities.