Do not downvote questions for being 'simple' to you. What one might find trivial another may find helpful. It is not in the spirit of SE. That being said,...
I have a line with the equation $y = -2.08x - 44$, and I must find the perpendicular equation, which will be $y \approx 0.4808x - b$.
Using the given coordinates $(0,0)$ for the $\perp$ line, I get $b = 0$. Now I can set the two lines equal to each other to solve for y, since the y values must be the same at an intersection: $-2.08x - 44 = 0.4808x$. I get $-2.5608x = 44$, and I can then multiply both sides by (1 / -2.5608) = -0.3905 to get $x = 112.676$. I then insert that back into the first equation to get $y = -2.08 * 112.676 - 44 = -278.36608$, so that I have $(112.676,278.367)$ which is not the correct answer, since an online calculator states that they intersect at $(-17, -8)$.
My question is, where in this process am I mistaken? Please tell me so that I can correct my errors and understand where I went wrong.