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:
[tex]\left[\begin{array}{ccc}1&1&1\\1&1&-1\\0&1&-1\end{array}\right][/tex][tex]\left[\begin{array}{c}x&y&z\end{array}\right]=[/tex][tex]\left[\begin{array}{c}239&59&25\end{array}\right][/tex].
