Answer:
r = 3
Step-by-step explanation:
x^2 + 6x + y^2 - 8y = - 16
Take half the linear term and square it.
x^2 + 6x + (3)^2 + y^2 - 8y + (-4)^2 = - 16
Add the squared amounts to the right.
x^2 + 6x + 9 + y^2 - 8y + 16 = - 16 + 9 + 16
Combine on the right.
x^2 + 6x + 9 + y^2 - 8y + 16 = 9
Represent the 2 quadratics as perfect squares.
(x + 3)^2 + y - 4)^2 = 9
The radius is the square root of 9 which is 3
$2,900 you have to subtract from the $4,000 and it is $1,100 you have left
11. 9/20
12. 13/20
13. 12/20
that's if it doesn't have to be in percentage form
Answer:
0.9855 or 98.55%.
Step-by-step explanation:
The probability of each individual match being flawed is p = 0.008. The probability that a matchbox will have one or fewer matches with a flaw is the same as the probability of a matchbox having exactly one or exactly zero matches with a flaw:

The probability that a matchbox will have one or fewer matches with a flaw is 0.9855 or 98.55%.