Answer:
x = ± 2
Step-by-step explanation:
Given
x² = 20 ( take the square root of both sides )
x = ± 
= ± 
= ± 2
Width=w
length=(40-2w)/2=20-w
A=w(40-w)
A=40w-w²
A'=40-2w=0
2w=40
w=20
20x20 is the size of the pen having the greatest area. this tells us the largest rectangle for a given perimeter is a square
Answer:
if we have the point (x, y), a reflection over the x-axis give us the point (x, -y)
if we have the point (x, y), a reflection over the y-axis give us the point (-x, y)
if we have the point (x, y), a reflection across both axes give us the point (-x, -y)
1. (2, -3) → (-2, -3) ------- reflection across the y-axis
2. (2, -3) → (-3, 2) -------- not a reflection
3. (2, -3) → (-2, 3) ------ reflection across both axes
4. (2, -3) → (2, 3) ----- reflection across the x-axis
-117 must be added to complete the square.
