How do you find the x and y intercepts for 4x-2y=8?

2 Answers
Nov 16, 2015

Rearrange into the form y=mx+c and substitue it x and y values of 0.

Explanation:

Rearrange into the form y=mx+c

To rearrange into the form y=mx+c we need to get y on its own. To do this we can take 4x away from both sides to get:

-2y = 8-4x

Next we'll multiply both sides by -1 to flip the signs:

2y = 4x-8

Finally we'll divide by 2:

y = 2x-4

Finding the x intercept
On the x axis we know that the y value is alwways 0 so we can substitute this into the equation and rearrange to find an x value.

0=4x-8

Add 8 to both sides:

8=4x

Divide by 4:

x=2

So we know the x intercept is at the point (2,0)

Finding the y intercept

At the y intercept we know that the x value is always 0.

Finding the y value is easy. The c value in y=mx+c gives the y coordinate for the y intercept and we've already rearrange into that form we now know that the y value is -4!

So the y intercept is at the point (0,-4)

Nov 16, 2015

x-intercept: 2
y-intercept: -4

Explanation:

Given: 4x-2y=8

x-intercept
The x-intercept is the value of x when y=0
color(white)("XXX")4x-2(0)=8 rArr x=2

y-intercept
The y-intercept is the value of y when x=0
color(white)("XXX")4(0)-2y=8 rArr y=-4