Answer:
X=6
Step-by-step explanation:
5(x-1)+3x=7(x+1)
5x-5+3x=7x+1
8x-5=7x+1
8x-7x=1+5
X=6
So the answer is X=6
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)
4- distributive property
Reason
X(y+u)= xy+xu
Expansion is distributive property
Hope it helps
To get this answer you would have to have a pace calculator!
Answer:
3
Step-by-step explanation:
3(1)² - 5(1) + 1
3x3 = 9
9-5+1
9-6 = 3