Question

How do you graph `x-4y=18`?

Answer 1

Graph as shown below:

Explanation:

One way of doing this is by finding two points on the graph, then connecting them up, so here we will find two points:

Finding the `y` - intercept: `=> x = 0`

`=> (0) -4y = 18`

`=> (cancel(-4)y)/(cancel(-4)) = (3*3*cancel(2))/(-2*cancel(2))`

`y = -9/2 => (0,-9/2)` Our first point

Finding the `x` - intercept `=> y = 0`

`=> x + (-4*0) = 18`

`x = 18 => (18,0)` Our second point

Now plotting these points on a graph:

Now joining these points up to yield a line graph:

Then there is our line, this will only really work for lines, when you advance further you will study things called quadratics, these are more difficult to graph!