I gotchu
The perimeter is 35. If we were to change the width, which is one of the dimensions of the flower bed, The perimeter will change. This means that perimeter will no longer be 35. So in order to keep the perimeter as it is, if we change one dimension, we must also change the other.
Let's solve for the length, using the formula to see how much the length changes from.
p = 2l + 2w
35 = 2l + 2(15)
35 = 2l + 30
5 = 2l
2.5 = l
We must increase the length from 2.5 feet. This is because decreasing one dimension will decrease the perimeter. But if we increase the other dimension as well, it will restore the perimeter to where is was initially.
the rule is look for the same number.
Let the lengths of the east and west sides be x and the lengths of the north and south sides be y. the dimensions you want are therefore x and y.
The cost of the east and west fencing is $4*2*x; the cost of the north and south fencing is $2*2*y. We have to put in that "2" because there are 2 sides that run from east to west and 2 sides that run from north to south.
The total cost of all this fencing is $4(2)(x) + $2(2)(y) = $128. Let's reduce this by dividing all three terms by 4: 2x + y = 32.
Now we are to maximize the area of the vegetable patch, subject to the constraint that 2x + y = 32. The formula for area is A = L * W. Solving 2x + y = 32 for y, we get y = -2x + 32.
We can now eliminate y. The area of the patch is (x)(-2x+32) = A. We want to maximize A.
If you're in algebra, find the x-coordinate of the vertex of this quadratic equation. Remember the formula x = -b/(2a)? Once you have calculated this x, subst. your value into the formula for y: y= -2x + 32.
Now multiply together your x and y values to obtain the max area of the patch.
If you're in calculus, differentiate A = x(-2x+32) with respect to x and set the derivative equal to zero. This approach should give you the same x value as before; the corresponding y value will be the same; y=-2x+32.
Multiply x and y together. That'll give you the maximum possible area of the garden patch.
The anwser is 40 becuase when you add 24+16=40
100 x 20 = 2000
Explanation
100
X
20
——
2000
