Answer:
Step-by-step explanation:
Answer "A"
Dodecahedron
No shel will not have enough tile. If you don't know the dimensions of the actual tile how will you solve. If you have a closet 18 square feet it could be 9 ' x 2 ' = 18 square feet. If the tiles were 12" x 6" you would need 36 tiles. If the closet was 6' x 3' = 18 square feet you could have the tiles 12" x 6" = 36 tiles. So you need to know the dimensions of the tile.
That would be :
4x – 10 = x2 – 5x + 10 ( y = 4x - 10 is substitute for y)
PROOF: y + 5x = x²<span> + 10
</span> (4x - 10) + 5x = x² + 10
4x - 10 = x² -5x + 10
<span>
</span>0 = x2 – 9x + 20<span> (liked terms are grouped and simplified)
PROOF: </span> 4x - 10 = x² -5x + 10
4x = x² -5x + 10 + 10
0 = x² -5x -4x + 20
0 = x² - 9x + 20
Solving:
x² - 9x + 20 = 0
x² - 5x - 4x + 20 = 0
(x - 5) (x - 4) = 0
⇒ x = 4 (as question says) OR x = 5