Get 0 on the right by adding -x to both sides:
Let y=0
Then we can write the above as this system of equations:
Now we draw the graph of the first equation by getting
some points:
x | y
------
-3 | 8
-2 | 2
-1 |-2
0 |-4
1 |-4
2 |-2
3 | 2
4 | 8
Draw a smooth curve through those points
Now the graph of the other equation in the system, y=0,
is simply the x-axis, so we only need to know the points where
the graph intersects the x-axis.=, and they will be the
solutions to the system
Notice that they cross at the short green lines below:
The x-intercept on the left is a little more than half way between
-1 and -2, so "guess"timate it to be -1.6.
The x-intercept on the right is a little more than half way between
2 and 3, so "guess"timate it to be 2.6.
So the solutions are about x = -1.6 and x = 2.6.
Edwin
