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.
They are equal because you can measure the percentage as a decimal with a maximum of 1.
Answer:
well, we only no that
2l + 2w is 80
(lengths and widths on all 4 sides
and that w * l is A
so the function should be w times what's left for l, but also expressed by something with w
2l + 2w = 80 | -2w
2l = 80 -2w | devide by 2
l = 80 - w
now we can substitute l in
A = w * l
so that we only need w's
A(w) = w * (80-w)
for any w it will give us the area, makes only sense for 0<w<80
Answer:
2 lbs 9 oz
Step-by-step explanation:
Lets line up the ounces and pounds and subtract
5 lb. 10 oz.
− 3 lb. 1 oz.
------------------------
2 lbs 9 oz
3^5) (x + 2)^(3/2) + 3 = 27
<span>(x + 2)^(3/2) = 24 / 243 </span>
<span>x + 2 = [ 24 / 243 ]^(2/3) </span>
<span>x + 2 = [ 8 / 81 ]^(2/3) </span>
<span>x = [ 4 / 81^(2/3) ] - 2 =-1.786
the answer is x=-1.786</span>
