The correct answer is -2 I just took the test.
So that is equal to 180 miles per 2 hours which is 90 miles per hour if each hour has the same m/hr rate.
You can set up a proportion:
let x = number of miles per hour

cross multiply and you get
2x=180
divide both sides by 2 and you get
x=90
so you get the same answer both ways,
90 miles per hour
Since he is using 3x more flower than the original, you would multiply the 2 tsp by 3 as well
6tsp is the answer
-5x - 6y = -21
5x - y =. 84
-7y = 63
y= -9
-5x = -21 - 54
-5x = -75
x = 15