Answer:
Dimensions :
x (the longer side, only one side with fence ) = 90 ft
y ( the shorter side two sides with fence ) = 45 ft
Total fence used 45 * 2 + 90 = 180 ft
A(max) =
Step-by-step explanation: If a farmer has 180 ft of fencing to encloses a rectangular area with fence in three sides and the river on one side, the farmer surely wants to have a maximum enclosed area.
Lets call "x" one the longer side ( only one of the longer side of the rectangle will have fence, the other will be along the river and won´t need fence. "y" will be the shorter side
Then we have:
P = perimeter = 180 = 2y + x ⇒ y = ( 180 - x ) / 2 (1)
And A (r) = x * y
A(x) = x * ( 180 - x ) /2 ⇒ A(x) = (180/2) *x - x² / 2
Taking derivatives on both sides of the equation :
A´(x) = 90 - x
Then if A´(x) = 0 ⇒ 90 - x = 0 ⇒ x = 90 ft
and from : y = ( 180 - x ) / 2 ⇒ y = 90/2
y = 45 ft
And
A(max) = 90 * 45 = 4050 ft²
Answer:
6hours
Step-by-step explanation:
From the given information:
Suppose it took Karl x hours to retile her bathroom,
Then it will take Della 3 hours longer i.e (3+x) hours
If Della and Karl work together or will take them 2 hours
The objective is to determine how long it will take Delia to retile the bathroom alone?
∴
By cross multiplying, we have:
2(2x+3) = 3x+x²
4x + 6 = 3x + x²
3x + x² - 4x - 6
x² - x - 6 = 0
Using quadratic equation
x² -3x +2x - 6 = 0
x(x - 3) + 2(x - 3) = 0
(x +2) (x - 3) = 0
x + 2 = 0 or x - 3 = 0
x = -2 or x = 3
Since we are concerned about the positive integer,
Then, Karl = x = 3 hours while Della which is (3+x) = 3+3 = 6hours
5/12 - 4/5 = -23/60. You can't simplify -23/60. Hope this is right
Answer:
81?
Step-by-step explanation
i might be wrong, if am delete this haha
