Answer:
1) 3x+3y-12
2) 4a-4b
4) 7t-98
5) 6x-54
7) 8m-4n
8) -3x+18y
180/3 60 second
Step-by-step explanation:
21/7 = 3 feet per second
4 times it is tails
Sample Space: 1H, 1T, 2H, 2T, 3H, 3T, 4H, 4T
H= heads
T= tails
Event is is tails; 1T, 2T, 3T, 4T
4 times or 50% chance