Answer:
1250 m²
Step-by-step explanation:
Let x and y denote the sides of the rectangular research plot.
Thus, area is;
A = xy
Now, we are told that end of the plot already has an erected wall. This means we are left with 3 sides to work with.
Thus, if y is the erected wall, and we are using 100m wire for the remaining sides, it means;
2x + y = 100
Thus, y = 100 - 2x
Since A = xy
We have; A = x(100 - 2x)
A = 100x - 2x²
At maximum area, dA/dx = 0.thus;
dA/dx = 100 - 4x
-4x + 100 = 0
4x = 100
x = 100/4
x = 25
Let's confirm if it is maximum from d²A/dx²
d²A/dx² = -4. This is less than 0 and thus it's maximum.
Let's plug in 25 for x in the area equation;
A_max = 25(100 - 2(25))
A_max = 1250 m²
Answer:
153.94
Step-by-step explanation:
The formula for area is pi*radius^2
the radius is 7, so we do pi7^2 which is 49pi
49pi is 153.93804 which is 153.94 rounded to two decimal places
Answer:
line 2 of her working
Step-by-step explanation:
when multiplying the brackets out it is a negative times posative so she should have wrote -4 not +4
Answer:
x = 5/33 or 0.151515151
Step-by-step explanation:
7(-6x-2) = 8(3x-4)
step 1: simplify the equation.
-42x - 14 = 24x - 4
step 2: isolate the variable (using the balance method).
-42x - 14 + 14 = 24x - 4 + 14
-42x = 24x + 10
-42x - 24x = 24x - 24x + 10
-66x = 10
step 3: solve for x.
x = 10 ÷ -66
x = 5/33
