9.

Solve the equation by factoring.

c2 − 4c = 0

c = 0 or c = 4

c = 1 or c = –

c = 0 or c = –4

c = 0 or c =

1 answer

To solve the equation \( c^2 - 4c = 0 \) by factoring, follow these steps:

1. **Factor the equation:** The given equation is \( c^2 - 4c = 0 \). First, factor out the common factor \( c \):
\[
c(c - 4) = 0
\]

2. **Set each factor equal to zero:** For the product to be zero, at least one of the factors must be zero. So set each factor equal to zero and solve for \( c \):
\[
c = 0
\]
and
\[
c - 4 = 0 \implies c = 4
\]

So, the solutions to the equation \( c^2 - 4c = 0 \) are \( c = 0 \) and \( c = 4 \).

Thus, the correct answer is:
\[ c = 0 \text{ or } c = 4 \]