Saw the quadologic equation 5x + 75x = 0 by factoring out the GCF

To solve the equation \( 5x + 75x = 0 \) by factoring out the greatest common factor (GCF), we first need to combine the terms on the left-hand side.

1. Combine the like terms:
\[
5x + 75x = (5 + 75)x = 80x
\]

So, we can rewrite the equation as:
\[
80x = 0
\]

2. Now, we can factor out the GCF, which is \( 80 \):
\[
80x = 0
\]

3. To solve for \( x \), we set the equation to zero and divide by \( 80 \):
\[
x = 0
\]

Thus, the solution to the equation \( 5x + 75x = 0 \) is:
\[
\boxed{0}
\]