Question 415640
this equation is in the form of y = mx + b where m is the slope and b is the y intercept.


f(x) = y = -8x - 4


m = -8 = slope


b = -4 = y intercept


graph of this equation is shown below:


{{{graph(600,600,-5,5,-50,50,-8x-4)}}}


the equation that is graphed is y = -8x - 4


the y intercept is the value of y when x equals 0.


when x = 0, y = -4.


the slope is -8.


you can see this by tracking the change in y divided by the change in x.


when x = 0, y = -4
when x = 1, y = -12
when x = 2, y = -20


let x1,y1 = 0,-4
let x2,y2 = 2,-20


x2-x1 = 2 - 0 = 2
y2 - y1 = -20 - (-4) = -16


change in y divided by change in x = -16 / 2 = -8 which is your slope.


you can also see that the graph of the equation crosses the y axis when y = -4.


the value of y when x equals 0 falls on the y-axis.