Answer:
0.5hrs
Step-by-step explanation:
Let the speed downhill be
,
Speed uphill is
. We are told than speed uphill is
the speed on flat ground. Therefore the speed on level ground will be
.
From this info, we can obtain the actual speed,
on level ground as:

speed, distance and time have the relation
so to obtain time to cover 45miles:

Hence it takes 0.5hrs to cover 45miles on flat ground.
385 + 326 + 298 = 1,009 / 3 = 336.33
385 + 326 + 298 + x = 350
350 x 4 = 1,400
1,400 - 1,009 = 391
385 + 326 + 298 + 391 = 1,400 / 4 = 350
The answer is $391
Perform indicated multiplication:
11c+3(-5c)+3(4d)
11c-15c+12d combine like terms
(11c-15c)+12d
-4c+12d factor
4(3d-c)
I prefer to use compatible numbers because by using this method it is easier to make a sum mentally. This is true because compatible numbers are close in value to the actual numbers. For a better understanding, let's take an example:
Suppose you have two numbers, namely 640 and 40. These two numbers are compatible for division because:
64 ÷ 4 = 16
So, we have used mental arithmetic to solve a more complex problem.
The perimeter of a shape is the sum of the lengths of its sides.
So, to find the perimeter of this quadrilateral, all we have to do is add the side lengths and simplify.
(x² - 6) + (2x + 5) + (x² - 3x) + (4x² + 2x)
x² + x² + 4x² + (-3x) + 2x + 2x + (-6) + 5
6x² + (-3x) + 2x + 2x + (-6) + 5
6x² + x + (-6) + 5
6x² + x + (-1)
6x² + x - 1
So, the perimeter of the quadrilateral is the quantity (6x² + x - 1).
Hope this helps!