To find the linear equation for the total cost \( c \) to carpet \( r \) rooms, we need to consider both the cost per room and the flat installation fee.
- Cost per room: $100 per room, so for \( r \) rooms, the cost is \( 100r \).
- Flat installation fee: $50.
Now, we can write the total cost equation as follows:
\[ c = 100r + 50 \]
This is already in slope-intercept form, \( c = mx + b \), where:
- \( m \) (the slope) is the cost per room (100),
- \( b \) (the y-intercept) is the installation fee (50).
So the final equation representing the total cost to have floors carpeted is:
\[ c = 100r + 50 \]