How do you find the x and y intercept of #8x − 3y = −21#?

1 Answer
Mar 24, 2017

Answer:

See the entire solution process below:

Explanation:

To find the intercepts by substitution we must do the following:

y-intercept - substitute #0# for #x# and solve for #y#:

#8x - 3y = -21# becomes:

#(8 xx 0) - 3y = -21#

#0 - 3y = -21#

#-3y = -21#

#(-3y)/color(red)(-3) = (-21)/color(red)(-3)#

#(color(red)(cancel(color(black)(-3)))y)/cancel(color(red)(-3)) = 7#

#y = 7#

The y-intercept is #7# or #(0, 7)#

x-intercept - substitute #0# for #y# and solve for #x#:

#8x - 3y = -21# becomes:

#8x - (3 xx 0) = -21#

#8x - 0 = -21#

#8x = -21#

#(8x)/color(red)(8) = (-21)/color(red)(8)#

#(color(red)(cancel(color(black)(8)))x)/cancel(color(red)(8)) = -21/8#

#x = -21/8#

The x-intercept is #-21/8# or #(-21/8, 0)#