Answer:
A
Step-by-step explanation:
This explanation mostly depends on what you're learning right now. The first way would be to convert this matrix to a system of equations like this.
g + t + k = 90
g + 2t - k = 55
-g - t + 3k = 30
Then you solve using normal methods of substitution or elimination. It seems to me that elimination is the quickest method.
g + t + k = 90
-g - t + 3k = 30
____________
0 + 0 + 4k = 120
4k = 120
k = 30
No you can plug this into the first two equations
g + t + (30) = 90
g + t = 60
and
g + 2t - (30) = 55
g + 2t = 85
now use elimination again by multiplying the first equation by -1
g + 2t = 85
-g - t = -60
_________
0 + t = 25
t = 25
Now plug those both back into one of the equations. I'll just do the first one.
g + (25) + (30) = 90
g = 35
Therefore, we know that Ted spent the least amount of time on the computer.
The second method is using matrix reduction and getting the matrix in the row echelon form, therefore solving using the gauss jordan method. If you would like me to go through this instead, please leave a comment.
Answer:
2600 feet every 3 minutes.
Every minute, he goes down about 866 feet.
Answer:
0.0025 = 0.25% probability that both are defective
Step-by-step explanation:
For each item, there are only two possible outcomes. Either they are defective, or they are not. Items are independent of each other. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
5 percent of these are defective.
This means that 
If two items are randomly selected as they come off the production line, what is the probability that both are defective
This is P(X = 2) when n = 2. So


0.0025 = 0.25% probability that both are defective
SimplifyingY + -9 = 4(x + -2)
Reorder the terms:-9 + Y = 4(x + -2)
Reorder the terms:-9 + Y = 4(-2 + x)-9 + Y = (-2 * 4 + x * 4)-9 + Y = (-8 + 4x)
Solving-9 + Y = -8 + 4x
Solving for variable 'Y'.
Move all terms containing Y to the left, all other terms to the right.
Add '9' to each side of the equation.-9 + 9 + Y = -8 + 9 + 4x
Combine like terms: -9 + 9 = 00 + Y = -8 + 9 + 4xY = -8 + 9 + 4x
Combine like terms: -8 + 9 = 1Y = 1 + 4x
SimplifyingY = 1 + 4x
That is correct.
Sqrt 5 x sqrt20
Apply the radical rule to get sqrt( 5 x 20)
Simplify to get sqrt(100)
Sqrt(100) = 10