X - 1 < = 9 or 2x > = 24
x < = 9 + 1 x > = 24/2
x < = 10 x > = 12
closed circle on 10, shaded to the left
closed circle on 12, shaded to the right
________10_______12__________
<====X X======>
the X represents closed circles
2 rows of geraniums and 4rows of the other one
The commutative property states that you can invert the order of the terms of a sum:

So, if you start with

Applying the commutative property you'll get

Answer:
The surface area is equal to 
Step-by-step explanation:
The surface area of the triangular pyramid is equal to the area of its four triangular faces
so
In this problem
![SA=4[\frac{1}{2}(b)(h)]](https://tex.z-dn.net/?f=SA%3D4%5B%5Cfrac%7B1%7D%7B2%7D%28b%29%28h%29%5D)
we have


substitute the values
![SA=4[\frac{1}{2}(15)(13)]=390\ in^{2}](https://tex.z-dn.net/?f=SA%3D4%5B%5Cfrac%7B1%7D%7B2%7D%2815%29%2813%29%5D%3D390%5C%20in%5E%7B2%7D)
the Reflexive Property of Equality