A farmer plans to fence a rectangular garden next to a river. There will be no fence along the river side. Draw a picture of this situation. The pasture will contain 405,000 square meters. Find the dimensions of the garden that will require the least amount of fencing.

x  =  450 m

y =  900 m

P (min)  = 1800 m

Step-by-step explanation:

Let´s call   "x"  and  "y" de sides of the rectangular garden, y is the side parallel to the river ( that is it will be fenced only one )

Then:

2*x + y = P        ( perimeter of the area)

And   x * y  = 405000 m²

y = 405000/ x

And P as a function of x is:

P(x) = 2*x +  405000/x

Tacking derivatives relative to x on both sides of the equation.

P´(x)  = 2  - 405000/x²

P´(x) =  0      2*x²  - 405000 = 0

x²  = 202500

x = 450 m

And y =  405000 / 450

y = 900 m

And

P(min) = 2*450 + 900

P(min) = 1800 m

We know P is minimm at x =450 snce the second derivative of P

P´´(x) = 405000*2*x / x⁴   is always positive

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!

50- 250 is correct i did that one too

step-by-step explanation: