To answer this item, we have 4 as the speed of the kayaker in still water and the speed of current be y.
When the karayaker moves upstream or against the current, his speed would be 4 - y. Further, if he moves downstream or with the current, the total speed would be 4 + y. The time utilized for the travel is equal to the ratio of the distance and the speed.
Total time = 9/(4 - y) + 9/(4 + y) = 6
We multiply the equation by (4-y)(4+y)
9(4-y) + 9(4 + y) = 6(4-y)(4+y)
Simplifying,
72 = 96 - 6y²
Transposing all the constants to only one side of the equation and rearranging,
6y² = 96 - 72
y² = 4
y = 2
Hence, the speed of the river's current is 2 miles/hr. <em>The answer is letter B.) 2 miles/hour.</em>
Answer:
Multiply the number of notebooks by the weight of one notebook.
When multiplying a whole number by a fraction, multiply the whole number by the top number of the fraction, and then divide that by the bottom number of the fraction.
56 x 5 = 280
280 / 8 = 35
The 56 notebooks weigh 35 pounds.
1 and 4
1² = 1 and 2² = 4 and 1 < 3 < 4
Answer:
Step-by-step explanation:
41 = 12d - 7
Adding 7 to both sides
41+7 = 12d
48 = 12 d
Dividing both sides by 12
4 = d
OR
d = 4
Answer:
The constant is 140 and it represent the minimum amount of money they'll make from selling hotdogs when the price is not raised.
Step-by-step explanation:
You're given the equation
y = -8x² + 54x + 140
The result from calculating the equation will give you how much money they made at the end of the day. And x is the amount of $1 price increase they had on the hotdog.
So we assume that they didn't raise the hotdog price at all (so x=0), then we would get:
y = -8(0)² + 54(0) + 140
y = 0 + 0 + 140
y = 140
Read further if you want more explanation...
So if they didn't increase their price at all, they would make at least $140.
Now lets plug in x=1 for a $1 increase in price.
we get
y = -8(1)² + 54(1) + 140
y = 186
ok, we see that the amount of money they made increased to $186 when they raise the price.
Now lets check when we raise the price by $2 (x=2)
y = -8(2)² + 54(2) + 140
y = 216
ok, now the revenue increased to $216
Just one last check, lets see what happen when we raise the price by $3 (x=3)
y = -8(3)² + 54(3) + 140
y = 230
Price increased again to $230.
As you can see, the 140 represent the revenue they make when the price is not raised at all (x=0).