How to find the x and y-intercept given 2x-y=4?

1 Answer
Shura
May 18, 2015

The x-intercept is the point P_1= (2, 0) and the y-intercept is the point P_2 = (0, -4)

Firstly, let's write your function in a standard form :

2x-y=4 => y=2x-4

When you seek the x-intercept, there is one information you know : the y value of the intercept, its ordinate = 0. Thus, you have a point (x, y) = (x, 0).

You can now replace the y in your equation with 0 :

0 = 2x - 4 => 2x = 4 => x = 2

The x-intercept is the point P_1 = (2, 0).

Same thing for the y-intercept except that the information you know is the x value of the intercept, the ordinate, which is = 0.
Thus, your have a second point (x, y) = (0, y).

Let's replace the x in the equation with 0 :

y = 2*0 - 4 = -4.

The y-intercept is the point P_2 = (0, -4).

That's it.

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