First, if you convert the improper fraction 9/2 to a mixed number, it will be equal to 9/2.
9/2 = 4 1/2
And if you multiply the top and bottom of a fraction with an integer number, you will have a fraction that is equal to fraction you began with.
I'll use 5 for this example.
9/2 * 5/5 = 45/10
It will be $3.68 for each rose bush because if she bought 6 of them for $22.08 then 22.08/6=3.68
So remember the formula for working out the slope:
(y2 - y1) ÷ (x2 - x1)
We already know two points:
(11, 5) and (20, 5) (Remember points are like (x, y)
Therefore y2 = 5 and y1 = 5 and x2 = 20 and x1 = 11
Substitute these into the formula from the start:
(y2 - y1) ÷ (x2 - x1)
(5 - 5) ÷ (20 - 11)
0 ÷ 9
And we can determine the slope is equal to 0 as 0 ÷ 9 = 0
2 because it's the highest exponent in the expression