Answer:
x ≠ -4
Step-by-step explanation:
Division by zero is not defined, so x cannot = -4.
Answer:
4 parameters are necessary to specify all solutions and correspond to the number of free variables of the system.
Step-by-step explanation:
Remember that the number of free variables of a system is equal to m-rank(A) where m is the number of unknowns variables and A is the matrix of the system.
Since the system is consistent and the rank of the matrix is 3 then echelon form of the augmented matrix has two rows of zeros.
Then m-rank(A)=7-3=4.
Answer:
30
Step-by-step explanation:
For this case we must follow the steps below:
step 1:
We place each of the given points on a coordinate axis
Step 2:
We join the AC points (represented by the orange line)
We join the BD points (represented by the blue line)
It is observed that the resulting figure after placing the 4 points on a coordinate axis, turns out to be a rhombus.
In addition, the blue and orange lines turn out to be perpendicular, that is, they have an angle of 90 degrees between them. This can be verified by finding the slopes of each of the two straight lines (blue and orange), which must be opposite reciprocal, that is, they comply: 
In this case, the slope of the orange line is
and that of the blue line is 
Then
, it is verified that they are perpendicular.
Thus, the conclusion is that ABCD is a rhombus and AC is perpendicular to BD.
Answer:
See attached image
Option D
Answer:
The correct answer is the last option.
Step-by-step explanation:
When you have a fraction with complex numbers, the first step to simplify is to multiply up and down the conjugate of the denominator, this will eliminate the complex part of the denominator, and in this way you can separate the expression in its real and complex part.
For the expression:

The denominator conjugate is 4 + 2i
When multiplied, the denominator is:
