Answer:
x=6f-7 is the correct answer.
40
Or at least that what my calculator says.
Answer
Find out the what is the surface area of the pyramid .
To proof
Formula
Surface area of a square pyramid

Where a is the base edge and h be the height .
As given
A square pyramid has a base with side lengths each measuring 40 inches. The pyramid is 21 inches tall, with a slant height of 29 inches.
i.e Base edge = 40 inches
Height = 21 inches
Put values in the above formula

solving



= 1600 + 80 × 29
= 3920 inches²
Therefore the surface area of the pyramid is 3,920 inches²
Hence proved
Step-by-step explanation:

let x be total much won

so they team had won 28 matches.
I hope the team has best players : )