3x-15+2x-2
=5x-17
use the distribution property
The answer to this problem would be -22
We know that
[lateral surface area of a regular triangular pyramid]=3*[area of one <span>equilateral triangle]
so
[area of one </span>equilateral triangle]=lateral surface/3-----> 81/3-----> 27 ft²
[<span>surface area of the regular triangular pyramid]=lateral area+area of the base
area of the base is equals to the area of the lateral sides because are </span>equilateral triangles
therefore
area of the base=27 ft²
[surface area of the regular triangular pyramid]=81+27----> 108 ft²
the answer is
<span>the surface area of the regular triangular pyramid is 108 ft</span>²
The answer is 48--- 64% of 75=48