I think the answer is option D hope it helps :)
Answer:
B
D
A
Step-by-step explanation:
Given:
A. 
B. 
C. 
D. 
Now, let us evaluate the given expressions one by one.

It is equation B.
So,
is equivalent to B.

It is equation D.
So,
is equivalent to D.

It is equation A.
So,
is equivalent to A.
So, answer is:
B
D
A
Answer:
Option a is the correct answer.
Step-by-step explanation:
Let x,y and z represent the marks scored in first,second and third tests respectively.
Total score is 239, then:
x+y+z = 239 -------1
Combined scores of first and second tests is 59 more than that of third test,then:
x+y = 59+z
x+y-z = 59 ---------2
The score of second test is 25 more than that of third test, then:
y = 25+z
0x+y-z = 25 --------3
The matrix equation for this situation is:
![\left[\begin{array}{ccc}1&1&1\\1&1&-1\\0&1&-1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%261%261%5C%5C1%261%26-1%5C%5C0%261%26-1%5Cend%7Barray%7D%5Cright%5D)
![\left[\begin{array}{c}x&y&z\end{array}\right]=](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%26y%26z%5Cend%7Barray%7D%5Cright%5D%3D)
.