Use completion of sq method
x^2+y^2+14x+10y-7=0
(x+7)^2+(y+5)^2=7+49+25
(x+7)^2+(y+5)^2=81
so centre is(-7,-5) radius is9
Answer:
$31.80
Step-by-step explanation:
The ball will cost 100% of its price plus 6% of its price for a total of 106%.
To use percentages as a factor and multiply, they must be divide by 100, making the multiplication factor version of 106% 1.06.
Multiply the cost of the ball by your multiplication factor:
30 x 1.06 = 31.8
Money is written to two decimal places, making your answer $31.80
Your answer would be 4.23 as the answer will be a long one, estimated.
The second bubble is the answer
Answer:
6.7% of children who finished the race in under 45 seconds.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 75 seconds
Standard Deviation, σ = 20 seconds
We are given that the distribution of time of completion is a bell shaped distribution that is a normal distribution.
Formula:
P(finished the race in under 45 seconds.)
P(x < 45)
Calculation the value from standard normal z table, we have,

6.7% of children who finished the race in under 45 seconds.