Answer:
I think it 7/18
Step-by-step explanation:
sorry if it is wrong
<span><span>x = x^2 - 30
or
x^2 - x - 30 = 0
Factors to
(x-6)(x+5) = 0
x = +6 is the positive number</span></span>
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
3.75 / 5 =0.75
0.75 x 8 = 6
So one yard is 6
Sorry, I’m not American so I don’t know about dollars but this should be correct x
