Answer:
Step-by-step explanation:
Scientific form of 0.0000007 = 7 ×
Kyle was given the following problem to solve.
2 answers:
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Answer:
<em>Thus, the dimensions of the metal plate are 10 dm and 8 dm.</em>
Step-by-step explanation:
For a quadratic equation:
The sum of the roots is -b and the product is c. Note the leading coefficient is 1.
We know the perimeter of the rectangular metal plate is 36 dm and its area is 80 dm^2. Being L and W its dimensions, then:
P=2(L+W)=36
A=L.W=80
Note both formulas are closely related to the roots of the quadratic equation, we only need to adjust the data for the perimeter to be exactly the sum of L+W and not double of it.
Thus we use the semi perimeter instead as P/2=L+W=18
The quadratic equation is, then:
Factoring by finding two numbers that add up to 18 and have a product of 80:
The solutions to the equation are:
x=10, x=8
Thus, the dimensions of the metal plate are 10 dm and 8 dm.
Answer:
0.231
Step-by-step explanation:
Let the Probability of students that knew the correct answer be: P(A)
P(A) = 60% = 0.6
Let the Probability that the student picked the wrong answer even if he/she knows the right answer be: P(B)
P(B) = 15% =0.15
Let the Probability of the student that do not knew the correct answer Be P(C)
P(C) = 1 - P(A)
P(C) = 1 - 0.6
P(C) = 0.4
Let the Probability that the student does not know the right answer but guessed it correctly be: P(D)
P(D) = 25% = 0.25
Let the Probability that the student picked the right answer even if he/she knows the right answer be: P(E)
P(E) = 1 - P(B)
P(E) = 1 - 0.15
P(E) = 0.85
Probability that the student got the answer wrong = (0.60 X 0.15) + (0.40 X 0.75) = 0.39
P( Student knew answer given he answered wrong) =
=
=
= 0.23076923077
= 0.231