Answer with Step-by-step explanation:
We are given that
A and B are matrix.
A.We know that for two square matrix A and B
Then, 
Therefore, it is true.
B. det A is the product of diagonal entries in A.
It is not true for all matrix.It is true for upper triangular matrix.
Hence, it is false.
C.

When is a factor of the characteristics polynomial of A then -5 is an eigenvalue of A not 5.
Hence, it is false.
D.An elementary row operation on A does not change the determinant.
It is true because when an elementary operation applied then the value of matrix A does not change.
Answer:
2a + 8b
Step-by-step explanation:
Answer: Square root of 200= 14.14ft
Hoped I Helped
(-7)*(2/5 + (-3/7))
= -14/5 + 3
=1/5
Answer:
Quarters = 20
Dimes = 14
Step-by-step explanation:
Dime = x = 10 cent = $0.1
Quarter = y = 25 cent = $0.25
x + y = 34 - - - (1)
0.1x + 0.25y = 6.40 - - - - (2)
From (1)
x = 34 - y
0.1(34 - y) + 0.25y = 6.40
3.4 - 0.1y + 0.25y = 6.40
3.4 + 0.15y = 6.40
0.15y = 6.40 - 3.40
0.15y = 3
y = 3 / 0.15
y = 20
x = 34 - y
x = 34 - 20
x = 14
Quarters = 20
Dimes = 14