9514 1404 393
Answer:
50 m/s
Step-by-step explanation:
Ian's rate was ...
(180,000 m)/(3600 s) = 50 m/s
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There are 1000 meters in a kilometer, and there are 3600 seconds in 1 hour. To find meters per second, divide meters by seconds.
Solution:
The difference of cubes identity is
if a and b are any two real numbers, then difference of their cubes , when taken individually:
→a³ - b³= (a-b)(a² + a b + b²)→→→Option (D) is true option.
I will show you , how this identity is valid.
Taking R H S
(a-b)(a² +b²+ab)
= a (a² +b²+ab)-b(a² +b²+ab)
= a³ + a b² +a²b -b a² -b³ -ab²
Cancelling like terms , we get
= a³ - b³
= L H S
Given, the rate of growth of St. Augustine grass is 
cm per week.
We have to find the number of weeks that the grass grow to 
cm.
Let's take the number of weeks be x.
In 1 week the grass grow = cm
So in x weeks the grass grow = 
cm
So we can write,
To solve it for x, first we will move 7 to the right side by multiplying it to both sides. We will get,
Now to get we will move 4 to the right side by dividing it to both sides. We will get,
So we have got the required answer.
After 3 weeks the grass grow 
.
Product is multiplication.
The opposite of 4 is -4
3 x -4 = -12
Answer: -12
