Im sure that it’s A, X = 2
Answer:
x = 28 m
y = 14 m
A(max) = 392 m²
Step-by-step explanation:
Rectangular garden A (r ) = x * y
Let´s call x the side of the rectangle to be constructed with a rock wall, then only one x side of the rectangle will be fencing with wire.
the perimeter of the rectangle is p = 2*x + 2*y ( but in this particular case only one side x will be fencing with wire
56 = x + 2*y 56 - 2*y = x
A(r) = ( 56 - 2*y ) * y
A(y ) = 56*y - 2*y²
Tacking derivatives on both sides of the equation we get:
A´(y ) = 56 - 4 * y A´(y) = 0 56 - 4*y = 0 4*y = 56
y = 14 m
and x = 56 - 2*y = 56 - 28 = 28 m
Then dimensions of the garden:
x = 28 m
y = 14 m
A(max) = 392 m²
How do we know that the area we found is a local maximum??
We find the second derivative
A´´(y) = - 4 A´´(y) < 0 then the function A(y) has a local maximum at y = 14 m
Let Ted be x.
Ed is 7 years older = x + 7
Ed = (3/4)Ted
(x + 7) = (3/4)x
x + 7 = 3x/4
x - 3x/4 = -7
x/4 = -7
x = -28, Ted = -28 years
(x + 7) = -28 + 7 = -21, Ed = -21 years.
Goodness. We had negative numbers for the ages, well does that make sense? No it doesn't.
Our answer is correct. But the sense in the question is lacking. The question has been wrongly set.
We might assume negative ages to mean before they came into the world, before birth!
Answer:
He must sell $14000 of merchandise
Step-by-step explanation:
The salesperson earns a base salary of $800
This means that he must make
$3600 - $800 = $2800 worth of commisions
Let x, be the value of the mechandise that he needs to sell.
This means that
x*0.20 = $2800
x = $2800/0.20
x = $14000
He must sell $14000 of merchandise
Answer:
3, 8, 12, 12, 14, 20, 21, 23, 26, 34
stem leaf
0 3 8
1 2 2 4 (you have 12,12,14)
2 0 1 3 6 ( numbers 20,21,23,26)
3 4 ( number 34)
