Find the intercepts of the graph of y = (x + 5)(x - 3)

Question

I know how to find the x and y intercepts but in an equation like y = 2x +1. This is a little confusing please help. Thank You!

Answer 1

Hi Zypher,

 

The answer comes from knowing what an intercept looks like in an equation. An X intercept is when you cross the x axis. This only happens when y=0. So, to find an X intercept we need to replace y with 0 and solve for x. 

 

0=(x+5)(x-3)

 

There are two answers for x in this case, -5 and 3. 

 

Y intercepts happen when we cross the Y axis which is at x=0. So, to find the Y intercepts we replace x with 0 and solve for y.

 

y=(0+5)(0-3)

y=5*-3

y=-15

 

I hope this helps.

 

Skyler