I believe the answer is $48 because 6 * 2 is 12 and 12 * 2 is 24 and 24 * 2 is 48, thus 48$. Please feel free to check my work, though.
The slope is 0 I’m pretty sure because it is a horizontal line, if it was a vertical line it would be undefined
(9y+y) + (6+3)
The answer is 10y+9