Answer:
x= 20 x =-5
Step-by-step explanation:
x^2 – 15x – 100 = 0.
What two numbers multiply to -100 and add to -15
-20 * 5 = -100
-20 +5 = -15
(x-20) (x+5) =0
Using the zero product property
x-20 =0 x+5 = 0
x= 20 x =-5
Answer:

Step-by-step explanation:
The surface area of a square pyramid is the sum of the area of the squared base + 4 times the area of each triangular face, therefore:

where:
is the area of the base, where
L is the length of the base
is the area of each triangular face, where
h is the height of the face
Substituting,

For the model in this problem,
L = 12
h = 8
Therefore, the surface area here is:

Answer:
Both are irrational
Step-by-step explanation:
is a trick as it does simplify to
, but that is irrational
Answer:
2 2
4y(2y +3y - 5) - 3(2y + 3y - 5)
3 2 2
=8y + 12y - 20y - 6y - 9y + 15
3 2
=8y + 6y - 29y + 15
Step-by-step explanation: