1.) -8 + 10(6 + 4r)
First multiply the 10 into (6 + 4r)
-8 + 60 + 40r
52 + 40r
2.) (8m² - 8m + 8) - (2m - 7m² - 6)
Distribute the - into (2m - 7m² - 6)
8m² - 8m + 8 - 2m + 7m² + 6
Combine like terms
15m² - 10m + 14
(idk if you need to factor this or if you can leave it as is)
Answer:



Step-by-step explanation:
Let
x----> the length of the rectangular garden
y---> the width of the rectangular garden
we know that
The perimeter of the rectangle is equal to

we have

so

simplify

------> equation A
Remember that the area of rectangle is equal to
----> equation B
substitute equation A in equation B
----> this is a vertical parabola open downward
The vertex is a maximum
The y-coordinate of the vertex is the maximum area
The x-coordinate of the vertex is the length side of the rectangle that maximize the area
using a graphing tool
The vertex is the point 
see the attached figure
so

Find the value of y

The garden is a square
the area is equal to
----> is equal to the y-coordinate of the vertex is correct
Answer:
2 inches
Step-by-step explanation:
a=Lw
v=lwh
lw= 7
14/7=2