8 is 7
9 is 0.666666666667
Answer:
x = ± 10
Step-by-step explanation:
To solve the equation let y = 0 , that is
0 = 100 - x²( add x² to both sides )
x² = 100 (I take the square root of both sides )
x = ±
= ± 10
Then solution is x = - 10, x = 10
The general formula for the lateral surface area of a regular pyramid is:

Where:
p=perimeter of a base
l=slant height
a.
a=3ft
l=4ft
p=5*a=5*3=15ft

b.
a=2.5ft
l=4ft
p=6*a=6*2.5=15ft

c.
a=1.9ft
l=4ft
p=8*a=8*1.9=15.2ft

d.
Based on a lateral surface area the blue umbrella is best choice. But, the best umbrella overall is the one with the greatest base area. General formula for regular polygon is:

For pentagon:
A=15.48ft^2
For hexagon:
A=16.24ft^2
For octagon:
A=17.43ft^2
Blue umbrella is still best choice.
Answer:
65
Step-by-step explanation:
180-115=65
It needs to be a total of 180 so just do what I did :)