This is the last exercise of the chapter and it combines the problems of all the important topics discussed in the chapter. Students wanting to strengthen their fundamentals and attain a good grip over the subject should use the Selina Solutions for Class 10 Maths. The solutions are prepared in a simple language according to the latest ICSE marking schemes. The solutions to the Concise Selina Solutions for Class 10 Maths Chapter 9 Matrices Exercise 9(D) can be effortlessly downloaded in PDF format from the links given below.
Selina Solutions Concise Maths Class 10 Chapter 9 Matrices Exercise 9(D) Download PDF
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Access Selina Solutions Concise Maths Class 10 Chapter 9 Matrices Exercise 9(D)
1. Find x and y, if:
Solution:
On comparing the corresponding terms, we have
6x – 10 = 8 and -2x + 14 = 4y
6x = 18 and y = (14 – 2x)/4
x = 3 and y = (14 – 2(3))/4
y = (14 – 6)/ 4
y = 8/4 = 2
Thus, x = 3 and y = 2
2. Find x and y, if:
Solution:
On comparing the corresponding terms, we have
3x + 18 = 15 and 12x + 77 = 10y
3x = -3 and y = (12x + 77)/10
x = -1 and y = (12(-1) + 77)/10
y = 65/10 = 6.5
Thus, x = -1 and y = 6.5
3. If; 
; find x and y, if:
(i) x, y ∈ W (whole numbers)
(ii) x, y ∈ Z (integers)
Solution:
From the question, we have
x2 + y2 = 25 and -2x2 + y2 = -2
(i) x, y ∈ W (whole numbers)
It can be observed that the above two equations are satisfied when x = 3 and y = 4.
(ii) x, y ∈ Z (integers)
It can be observed that the above two equations are satisfied when x = ± 3 and y = ± 4.
4. 
(i) The order of the matrix X.
(ii) The matrix X.
Solution:
(i) Let the order of the matrix be a x b.
Then, we know that
Thus, for multiplication of matrices to be possible
a = 2
And, form noticing the order of the resultant matrix
b = 1
(ii)
On comparing the corresponding terms, we have
2x + y = 7 and
-3x + 4y = 6
Solving the above two equations, we have
x = 2 and y = 3
Thus, the matrix X is 
5. Evaluate:
Solution:
6. 
3A x M = 2B; find matrix M.
Solution:
Given,
3A x M = 2B
And let the order of the matric of M be (a x b)
Now, it’s clearly seen that
a = 2 and b = 1
So, the order of the matrix M is (2 x 1)
Now, on comparing with corresponding elements we have
-3y = -10 and 12x – 9y = 12
y = 10/3 and 12x – 9(10/3) = 12
12x – 30 = 12
12x = 42
x = 42/12 = 7/2
Therefore,
Matrix M =
7. 
find the values of a, b and c.
Solution:
On comparing the corresponding elements, we have
a + 1 = 5 ⇒ a = 4
b + 2 = 0 ⇒ b = -2
-1 – c = 3 ⇒ c = -4
8. 
(i) A (BA) (ii) (AB) B.
Solution:
(i) A (BA)
(ii) (AB) B
9. Find x and y, if: 
Solution:
Thus, on comparing the corresponding terms, we have
2x + 3x = 5 and 2y + 4y = 12
5x = 5 and 6y = 12
x = 1 and y = 2
10. If matrix 
find the matrix ‘X’ and matrix ‘Y’.
Solution:
Now,
On comparing with the corresponding terms, we have
-28 – 3x = 10
3x = -38
x = -38/3
And,
20 – 3y = -8
3y = 28
y = 28/3
Therefore,
11. Given 
find the matrix X such that:
A + X = 2B + C
Solution:
12. Find the value of x, given that A2 = B,
Solution:
Thus, on comparing the terms we get x = 36.
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