Find the x-intercept....?

Question

Hello!!

I have the following equation: 4x+3y+12=0

I have put y as a function of x: f(x) = -4/3x - 4

I understand the y-intercept is -4? (Well I only know to take that last number above as it, not exactly where to find the y-intecept if it's not the last number..)

But what had totally stumped me is how to obtain the root (x-intercept). My only progress with this is:

0 = -4x/3 -4 (set it to 0)

I understand the next steps are as follows:

4 = -4x/3

x = -3

But I have literally NO idea what the process for that is? Can someone explain that in baby steps? I will incredibly incredibly grateful to anyone who can help me!! :]

Answer 1

The y-intercept is where the line (or function) crosses the y-axis, that is, where x = 0.

And, oddly enough, The x-intercept (root) is where the line (or function) crosses the x-axis, that is, where y (or the value of the function) = 0.

Answer 2

you have the equation of the line

4x + 3y + 12 = 0.

if you want the x-intercept of the line, first solve for x:

x = -3y / 4 - 3.

the x-intercept is the point where the line crosses the x-axis, that is, where y = 0. so, set y = 0

x = -3*0 / 4 - 3

  = -3.

so, the x-intercept is -3. your answer was quite right.