Answer:
i think it's 10.6
Step-by-step explanation:
112 = x^2
Answer:
Speed of the river = 
km per hour
Step-by-step explanation:
Speed of the boat in still water = 4 km per hour
Let the speed of the river = v km per hour
Speed of the boat upstream = (4 - v) km per hour
Time taken to cover 6 km = 
= 
hours
Speed of the boat downstream = (4 + v) km per hour
Time taken to cover 12 km = 
hours
Since, time taken by the boat in both the cases is same,
6(4 + v) = 12(4 - v)
24 + 6v = 48 - 12v
12v + 6v = 48 - 24
18v = 24
v = 
v = km per hour
Answer:
y = 30(2)^x
Step-by-step explanation:
Initial deer population = 30 (in 2010)
Every year, deer population doubles ; this means there is an 100% increase in the population every year ;
Hence, using the exponential growth relation :
Final = initial * (1 + rate)^year
Here,
Final population y ; x years after 2010
Rate = 100% = 1
Hence,
y = 30(1 + 1)^x
y = 30(2)^x
Answer:
pick number 3 I think that's the one
(a) x = 4
First, let's calculate the area of the path as a function of x. You have two paths, one of them is 8 ft long by x ft wide, the other is 16 ft long by x ft wide. Let's express that as an equation to start with.
A = 8x + 16x
A = 24x
But the two paths overlap, so the actual area covered will smaller. The area of overlap is a square that's x ft by x ft. And the above equation counts that area twice. So let's modify the equation by subtracting x^2. So:
A = 24x - x^2
Now since we want to cover 80 square feet, let's set A to 80. 80 = 24x - x^2
Finally, let's make this into a regular quadratic equation and find the roots.
80 = 24x - x^2
0 = 24x - x^2 - 80
-x^2 + 24x - 80 = 0
Using the quadratic formula, you can easily determine the roots to be x = 4, or x = 20.
Of those two possible solutions, only the x=4 value is reasonable for the desired objective.
(b) There were 2 possible roots, being 4 and 20. Both of those values, when substituted into the formula 24x - x^2, return a value of 80. But the idea of a path being 20 feet wide is rather silly given the constraints of the plot of land being only 8 ft by 16 ft. So the width of the path has to be less than 8 ft (the length of the smallest dimension of the plot of land). Therefore the value of 4 is the most appropriate.
