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)