# Selina Solutions Concise Maths Class 10 Chapter 9 Matrices Exercise 9(B)

Multiplication of a matrix by a scalar (real number) is the main concept discussed in this exercise. Students wishing to learn the correct steps of solving problems of the book can have a quick reference at the Selina Solutions for Class 10 Maths. All the solutions are prepared by subject experts at BYJUâ€™S which is on par with the latest ICSE marking schemes. The solutions to the Concise Selina Solutions for Class 10 Maths Chapter 9 Matrices Exercise 9(B) are accessible in PDF format provided in the links given below.

## Selina Solutions Concise Maths Class 10 Chapter 9 Matrices Exercise 9(B) Download PDF

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Exercise 9(A) Solutions

Exercise 9(C) Solutions

Exercise 9(D) Solutions

## Access Selina Solutions Concise Maths Class 10 Chapter 9 Matrices Exercise 9(B)

1. Evaluate:

(i) 3[5 -2]

Solution:

3[5 -2] = [3×5 3x-2] = [15 -6]

(ii)

Solution:

(iii)

Solution:

(iv)

Solution:

2. Find x and y if:

(i) 3[4 x] + 2[y -3] = [10 0]

Solution:

Taking the L.H.S, we have

3[4 x] + 2[y -3] = [12 3x] + [2y -6] = [(12 + 2y) (3x – 6)]

Now, equating with R.H.S we get

[(12 + 2y) (3x – 6)] = [10 0]

12 + 2y = 10 and 3x â€“ 6 = 0

2y = -2 and 3x = 6

y = -1 and x = 2

(ii)

Solution:

We have,

So, equating the matrices we get

-x + 8 = 7 and 2x â€“ 4y = -8

x = 1 and 2(1) â€“ 4y = -8

2 â€“ 4y = -8

4y = 10

y = 5/2

3.

(i) 2A â€“ 3B + C (ii) A + 2C – B

Solution:

(i) 2A â€“ 3B + C

(ii) A + 2C â€“ B

4.

Solution:

Given,

5.

(i) find the matrix 2A + B.

(ii) find a matrix C such that:

Solution:

(i) 2A + B

(ii)