Step-by-step explanation:

Answer:
y = -1/4 -5
Step-by-step explanation:
Any equation will be parallel to your base equation as long as the y intercept is different. To write a parallel equation, you just have to change the y intercept.
For example, I changed it from 2 to negative 5.
For this case we must find the solution of the following quadratic equation:

Where:

Then, the solution is given by:

Substituting the values:

By definition we have:

Thus, we have two complex roots.
Answer:
The equation has no real roots.
Answer:
The probability is 0.9211
Step-by-step explanation:
Let's call K the event that the student know the answer, G the event that the student guess the answer and C the event that the answer is correct.
So, the probability P(K/C) that a student knows the answer to a question, given that she answered it correctly is:
P(K/C)=P(K∩C)/P(C)
Where P(C) = P(K∩C) + P(G∩C)
Then, the probability P(K∩C) that the student know the answer and it is correct is:
P(K∩C) = 0.7
On the other hand, the probability P(G∩C) that the student guess the answer and it is correct is:
P(G∩C) = 0.3*0.2 = 0.06
Because, 0.3 is the probability that the student guess the answer and 0.2 is the probability that the answer is correct given that the student guess the answer.
Therefore, The probability P(C) that the answer is correct is:
P(C) = 0.7 + 0.06 = 0.76
Finally, P(K/C) is:
P(K/C) = 0.7/0.76 = 0.9211