Answer:
10 hours
Step-by-step explanation:
Two boats leave a port at the same time, one going north and the other traveling south.
<u>Southbound boat rate</u> = 40 mph
The northbound boat travels 18 mph faster than the southbound boat.
<u>Northbound boat rate</u> = 40 + 18 = 58 mph
Two boats rate = 40 + 58 = 98 mph (this means they are apart 98 km after one hour)
Total distance = 980 miles
Total rate = 98 mph
Time 
hours
The domain is "x", because that is what you input
hope this helps
20/21 (WORK AND EXPLANATION PROVIDED)
To find the perimeter of the square, you add all four sides together:
10x + 10x + (6x + 8) + (6x + 8)
20x + 12x + 16 = P
32x + 16 = P
you have to find x to get the actual perimeter. Since the shape is a square, all 4 sides are equal, so you can set 10x and (6x + 8) as equal to each other.
10x = 6x + 8
4x = 8
x = 2
Now you just plug in x and finish the rest of the problem, and you have the answer:
32(2) + 16 = P
64 + 16 = P
P = 80
(if you find this helpful, marking this as the brainliest answer would make my day :)
