How do you find the x and y intercept of 4x+8y=12?

2 Answers
Jan 7, 2017

Y int at (0,3/2)
X int at (3,0)

Explanation:

The line is easier to visualize when the equation is in slope-intercept form:
4x+8y=12

Divide each side by 4:
x+2y=3
2y=-x+3
y=-1/2x+3/2

Y-intercept (plug in 0 for x):
y=-1/2(0)+3/2
y=3/2

X-intercept (plug in 0 for y):
0=-1/2x+3/2
-3/2=-1/2x
x=3

Jan 7, 2017

To find the x intercept substitute 0 for y in the equation.

To find the y intercept substitute 0 for x in the equation.

See the full explanation below

Explanation:

To find the x intercept substitute 0 for y in the equation and solve for x.

4x + (8 xx 0) = 12

4x + 0 = 12

4x = 12

(4x)/color(red)(4) = 12/color(red)(4)

(color(red)(cancel(color(black)(4)))x)/cancel(color(red)(4)) = 3

x = 3

The x-intercept is 3 or (3, 0)

To find the y intercept substitute 0 for x in the equation and solve for y.

(4 xx 0) + 8y = 12

0 + 8y = 12

8y = 12

(8y)/color(red)(8) = 12/color(red)(8)

(color(red)(cancel(color(black)(8)))y)/cancel(color(red)(8)) = (4 xx 3)/(4 xx 2)

y = (cancel(4) xx 3)/(cancel(4) xx 2)

y = 3/2

The y-intercept is 3/2 or (0, 3/2)