Speed, S = Distance (d) / Time (t) => S= d/t => t= d/S
Let the speed of boat in still water be x mph
Resulting speed upstream = x-4 mph for a distance of 30 miles
Resulting speed downstream = x-4 mph for a distance of 50 miles
Time taken in both distances is equal.
Therefore,
30/(x-4) = 50/(x+4) => 30(x+4) = 50(x-4) => 30x+120 = 50x-200 => 120+200 = (50-30)x => 20x = 320 => x=320/20 = 16 mph
The speed of boat in still water is 16 mph.
Answer:
-8/25
Step-by-step explanation:
I took the test and i got it right
Multiply the two brackets together
(2x-1)(x-2)
2x(x)(2x*-2)(-1*x)(-1*-2)
2x^2-4x-x+2
2x^2-5x+2
Answer is 2x^2-5x+2 - J
25 root 3 divided by 2
Base is 5. Height is 5 root 3
Multiply then divide by 2
2/3-> 4/6
1/2-> 3/6
Subtract
1/6
2/5-> 16/40
1/8-> 5/40
Subtract
11/40