N<6 is the answer I think
Let s = northbound train
Then
2s = southbound train
:
Distance = time * speed
4s + 4(2s) = 600
:
4s + 8s = 600
:
12s = 600
:
s = 600/12
:
s = 50 mph is the northbound train
Then
2(50) = 100 mph is the southbound train
:
:
Check:
4(50) + 4(100) = 600
Answer:
1. Formula: b * h ÷ 2
12 * 3 = 36 ÷ 2 = 18 in^2
2. Formula: b * h ÷ 2
5 * 8 = 40 ÷ 2 = 20 ft^2
I could only help on two. Hope it helps though! =)
This picture will explain the mistake. She didn’t carry down the -2/4 and add to make sure her answer was fully correct.