Answer:
you subtract 43 to 91 so then you get 48
Step-by-step explanation:
Y = 9x - 2
3x - 2y = 7
so sub in 9x - 2 for y in the 2nd equation and solve for x
3x - 2(9x - 2) = 7
3x - 18x + 4 = 7
3x - 18x = 7 - 4
-15x = 3
x = -3/15
x = -1/5 or - 0.2 <===
This may be wrong, but from my math:
if you divide 8019 by 3 ,
you end up with 2,703.
So altogether they collected 2,703 bottle caps total.
Solving for the elapsed time
distance traveled = (speed of first train + speed of second train) * elapsed time
280 miles = (95 mph + 105 mph) * elapsed time
280 miles = 200 mph * elapsed time
elapsed time = 280 miles / 200 mph
elapsed time = 1.4 hours
elapsed time = 1 hour and 24 minutes
It will take 1 hour and 24 minutes for the two trains to be 280 miles apart.
