Answer:
C.
The equation that represents this situation is -3x = 21. The second number is -7.
Step-by-step explanation:
So total, Rita gets 128 dollars, in 8 days
Answer:
-1 <= x <= 1
Step-by-step explanation:
√((1-2x+x^2)+2-2x^2)
= √((1-x)^2 + 2*(1-x)(1+x) )
điều kiện là 1 - x > =0 và 1+x >=0
giải 2 bất phương trình trên ta thu đc kết ququả
Answer:
Step-by-step explanation:
The given quadratic form is of the form
.
Where 
.Every quadratic form of this kind can be written as
Observe that 
is a symmetric matrix. So is orthogonally diagonalizable, that is to say, 
where 
is an orthogonal matrix and 
is a diagonal matrix.
In our case we have:
The eigenvalues of are 
.
Every symmetric matriz is orthogonally diagonalizable. Applying the process of diagonalization by an orthogonal matrix we have that:
Now, we have to do the change of variables 
to obtain
Which can be written as:
