Answer:
$14
Step-by-step explanation:
1. Perimeter
22a + 2(6a + 8) -4 = p
[I got 22a from 12a + 10a]
2. If p = 250, what is a?
22a + 2(6a + 8) - 4 = 250
Distributive property
22a + 12a + 16 - 4 = 250
Add like terms
34a + 12 = 250
Subtract 12 by both sides
34a = 238
Divide 34 by both sides
a = 7
Answer: Below
Step-by-step explanation:
125% is essentially 1.25 or 125/100.
In mixed number form it's:
Answer:
A), B) and D) are true
Step-by-step explanation:
A) We can prove it as follows:
B) When you compute the product Ax, the i-th component is the matrix of the i-th column of A with x, denote this by Ai x. Then, we have that 
. Now, the colums of A are orthonormal so we have that (Ai x)^2=x_i^2. Then 
.
C) Consider 
. This set is orthogonal because 
, but S is not orthonormal because the norm of (0,2) is 2≠1.
D) Let A be an orthogonal matrix in 
. Then the columns of A form an orthonormal set. We have that 
. To see this, note than the component 
of the product 
is the dot product of the i-th row of 
and the jth row of 
. But the i-th row of is equal to the i-th column of . If i≠j, this product is equal to 0 (orthogonality) and if i=j this product is equal to 1 (the columns are unit vectors), then 
E) Consider S={e_1,0}. S is orthogonal but is not linearly independent, because 0∈S.
In fact, every orthogonal set in R^n without zero vectors is linearly independent. Take a orthogonal set 
and suppose that there are coefficients a_i such that 
. For any i, take the dot product with u_i in both sides of the equation. All product are zero except u_i·u_i=||u_i||. Then 
then 
.
