Answer:
The correct product is 6,252.
I don't know what Dan did wrong lol
Answer:

Step-by-step explanation:

Rearrange the equation by writing
x² + x - 90 = 0
x² + x = 90
x² + x + 1/4 = 90 + 1/4
Recall that (a + b)² = a² + 2ab + b². Then
x² + 2 • x/2 + (1/2)² = 361/4
(x + 1/2)² = 361/4
x + 1/2 = ± √(361/4)
x = -1/2 ± 19/2
x = 9 or x = -10
I think round mean shaped like a circle
It could be a deltahedron. A deltahedron has all faces being an equilateral triangle. The amount of faces can vary from 4, 6, 8, 10, 12, 14, 16 and 20.