Answer: The answer is 8.
Step-by-step explanation: The first step is to convert the expression into figures. We shall call the unknown number Y. So if we are told “the square of a number,” that means Y squared, or better still, Y^2. Further we are told “the difference between the square of a number and 40” and that can be written as;
Y^2 - 40.
Next we are told that this expression is equal to 3 times that number (that is 3Y). That can now be written out as follows,
Y^2 - 40 = 3Y
If we move all expressions to one side of the equation, what we would have is,
Y^2 - 3Y -40 = 0
(Remember that when a positive value crosses to the other side of an equation it becomes negative and vice versa)
We now have a quadratic equation
Y^2 -3Y - 40 = 0
By factorizing we now have
(Y -8) (Y + 5) = 0
Therefore Y - 8 = 0 or
Y + 5 = 0
Hence, Y = 8 or Y = -5
Since we are asked to calculate the positive solution, Y = 8
Answer:
22 people
Step-by-step explanation:
Answer: ok
Step-by-step explanation:
Answer:
Multiple answers
Step-by-step explanation:
The original urns have:
- Urn 1 = 2 red + 4 white = 6 chips
- Urn 2 = 3 red + 1 white = 4 chips
We take one chip from the first urn, so we have:
The probability of take a red one is : 
(2 red from 6 chips(2/6=1/2))
For a white one is: 
(4 white from 6 chips(4/6=(2/3))
Then we put this chip into the second urn:
We have two possible cases:
- First if the chip we got from the first urn was white. The urn 2 now has 3 red + 2 whites = 5 chips
- Second if the chip we got from the first urn was red. The urn two now has 4 red + 1 white = 5 chips
If we select a chip from the urn two:
- In the first case the probability of taking a white one is of:
= 40% ( 2 whites of 5 chips) - In the second case the probability of taking a white one is of:
= 20% ( 1 whites of 5 chips)
This problem is a dependent event because the final result depends of the first chip we got from the urn 1.
For the fist case we multiply :
x = 
= 26.66% ( the probability of taking a white chip from the urn 1, the probability of taking a white chip from urn two)
For the second case we multiply:
x = 
= .06% ( the probability of taking a red chip from the urn 1, the probability of taking a white chip from the urn two)
Answer:
Half of the total cost was paid when her braces were put on. The total cost is $3,200. How much will Kelly's parents need to save each month to pay off the ..
Step-by-step explanation:
