2 pairs of paralell sides

Remember, diameter = 2 x radius
Answer:
Step-by-step explanation:
ax² + bx + c = a(x -
)(x -
)
D = b² - 4ac
= ( - b ± √D ) / 2a
~~~~~~~~~~~~
Let x² = y , then y² + 8y - 9
Find the roots of equation y² + 8y - 9 = 0
D = 64 + 36 = 100 = 10²
= ( - 8 - 10) / 2 = - 9
= ( - 8 + 10) / 2 = 1
y² + 8y - 9 = (y - 1)(y + 9) = (x² - 1)(x² + 9)
x² = 1 ⇒
= ± √1
+ 8x² - 9 = (x - 1)(x + 1)(x² + 9)
The number is 'n'.
Five times the number is 5n .
Nine more than that is 5n + 9 .