Answer:
x = sqrt(11 - y) - 2 or x = -sqrt(11 - y) - 2
Step-by-step explanation:
Solve for x:
y = -x^2 - 4 x + 7
y = -x^2 - 4 x + 7 is equivalent to -x^2 - 4 x + 7 = y:
-x^2 - 4 x + 7 = y
Multiply both sides by -1:
x^2 + 4 x - 7 = -y
Add 7 to both sides:
x^2 + 4 x = 7 - y
Add 4 to both sides:
x^2 + 4 x + 4 = 11 - y
Write the left hand side as a square:
(x + 2)^2 = 11 - y
Take the square root of both sides:
x + 2 = sqrt(11 - y) or x + 2 = -sqrt(11 - y)
Subtract 2 from both sides:
x = sqrt(11 - y) - 2 or x + 2 = -sqrt(11 - y)
Subtract 2 from both sides:
Answer: x = sqrt(11 - y) - 2 or x = -sqrt(11 - y) - 2
Answer:
The answer is minus 7373838474
Step-by-step explanation:
Answer:
1 hour 20 minutes
Step-by-step explanation:
Time to fix car ( repair time ) = 20 minutes
Breakdown rate ( λ ) = 2 car per hour
<u>first step : determine service the service rate ( μ )</u>
= 60 minutes / 20 minutes
= 3 cars per hour
<u>next : determine the average waiting time for a disabled car </u>
= 1 / (μ - λ)
= 1 / service rate - breakdown rate
= 1 / ( 3 - 2 )
= 1 / 1 = 1 hour
Finally Total time for a disabled car to be fixed
= repair time + average waiting time
= 20 minutes + 60 minutes
= 1 hour 20 minutes
Answer:
17,19,21
Step-by-step explanation:
hope this helps
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