Question 561868
How do I find the x- and y- intercepts for the equation -3x-4y = 18
Put the equation into the slope/intercept form
-3x - 4y = 18
Add 3x to both sides
-4y = 3x + 18
divide both sides by -4
y = {{{3/(-4)}}}x + {{{18/(-4)}}}
y = -.75x - 4.5
:
The y intercept is easy, it occurs when x=0, so we have
y = =.75(0) - 4.5
y = -4.5 is the y intercept
:
The x intercept occurs when y = 0, write it
-.75x - 4.5 = 0
add 4.5 to each side
-.75x = 4.5
Divide both sides by -.75
x = {{{4.5/(-.75)}}}
x = -6 is the x intercept
:
:
Grph would look like this
{{{ graph( 300, 200, -10, 6, -10, 10, -.75x-4.5) }}} 
Note the x and y intercepts