Answer:
-1/2 is your answer.
Step-by-step explanation:
The slope formula is (y_2 - y_1)/(x_2 - x_1)
The y's are -3 and 2, while the x's are 9 and -1.
(-3-2)/(9-(-1))=-5/10=
9/5
the distance is 9 over, and 5 up.
$3.60.
If you want to tip 15%, then the total tip amount would be $2.40 plus half of that again ($1.20), which is $3.60.