Selina Solutions Concise Mathematics Class 6 Chapter 19 Fundamental Operations Exercise 19(A) provides answers in a step wise manner for better understanding of the concepts. The solutions help students in improving knowledge about the concepts, as per the current ICSE syllabus. Students can use these solutions, to get a new idea about the steps to be followed in solving the problems easily. Those who intend to speed up problem solving skills are advised to practice textbook questions using solutions designed by experts. Selina Solutions Concise Mathematics Class 6 Chapter 19 Fundamental Operations Exercise 19(A) PDF, links are given below for free download.
Selina Solutions Concise Mathematics Class 6 Chapter 19: Fundamental Operations Exercise 19(A) Download PDF
Access other exercises of Selina Solutions Concise Mathematics Class 6 Chapter 19: Fundamental Operations
Access Selina Solutions Concise Mathematics Class 6 Chapter 19: Fundamental Operations Exercise 19(A)
Exercise 19(A)
1. Fill in the blanks:
(i) 5 + 4 = …….. and 5x + 4x = ………
(ii) 12 + 18 = ……. and 12x2y + 18x2y = ……..
(iii) 7 + 16 = …….. and 7a + 16b = …….
(iv) 1 + 3 = ……. and x2y + 3xy2 = ……
(v) 7 – 4 = …… and 7ab – 4ab = ………
Solution:
(i) 5 + 4 = 9 and 5x + 4x = 9x
(ii) 12 + 18 = 30 and 12x2y + 18x2y = 30x2y
(iii) 7 + 16 = 23 and 7a + 16b = 7a + 16b
(iv) 1 + 3 = 4 and x2y + 3xy2 = x2y + 3xy2
(v) 7 – 4 = 3 and 7ab – 4ab = 3ab
2. Fill in the blanks:
(i) The sum of -2 and -5 = ……… and the sum of -2x and -5x = ……….
(ii) The sum of 8 and -3 = ……… and the sum of 8ab and -3ab = ………….
(iii) The sum of -15 and -4 = ……… and the sum of -15x and -4y = ………..
(iv) 15 + 8 + 3 = …….. and 15x + 8y + 3x = …………
(v) 12 – 9 + 15 = ………… and 12ab – 9ab + 15ba = ……….
Solution:
(i) The sum of -2 and -5 = – 7 and the sum of -2x and -5x = – 7x
(ii) The sum of 8 and -3 = 5 and the sum of 8ab and -3ab = 5ab
(iii) The sum of -15 and -4 = – 19 and the sum of -15x and -4y = – 15x – 4y
(iv) 15 + 8 + 3 = 26 and 15x + 8y + 3x = 18x + 8y
(v) 12 – 9 + 15 = 18 and 12ab – 9ab + 15ba = 18ab
3. Add:
(i) 8xy and 3xy
(ii) 2xyz, xyz and 6xyz
(iii) 2a, 3a and 4b
(iv) 3x and 2y
(v) 5m, 3n and 4p
Solution:
(i) 8xy and 3xy
The addition of 8xy and 3xy is calculated as follows
8xy + 3xy = 11xy
(ii) 2xyz, xyz and 6xyz
The addition of 2xyz, xyz and 6xyz is calculated as follows
2xyz + xyz + 6xyz = 9xyz
(iii) 2a, 3a and 4b
The addition of 2a, 3a and 4b is calculated as follows
2a + 3a + 4b = 5a + 4b
(iv) 3x and 2y
The addition of 3x and 2y is calculated as follows
3x + 2y = 3x + 2y
(v) 5m, 3n and 4p
The addition of 5m, 3n and 4p is calculated as follows
5m + 3n + 4p = 5m + 3n + 4p
4. Evaluate:
(i) 6a – a – 5a – 2a
(ii) 2b – 3b – b + 4b
(iii) 3x – 2x – 4x + 7x
(iv) 5ab + 2ab – 6ab + ab
(v) 8x – 5y – 3x + 10y
Solution:
(i) 6a – a – 5a – 2a
The value of given expression is calculated as below
6a – a – 5a – 2a = (6 – 1 – 5 – 2) a
We get,
= (5 – 5 – 2) a
= – 2a
Therefore, 6a – a – 5a – 2a = – 2a
(ii) 2b – 3b – b + 4b
The value of given expression is calculated as below
2b – 3b – b + 4b = 2b + 4b – (3 + 1) b
We get,
= 6b – 4b
= 2b
Therefore, 2b – 3b – b + 4b = 2b
(iii) 3x – 2x – 4x + 7x
The given expression is calculated as below
3x – 2x – 4x + 7x = 3x + 7x – 2x – 4x
= (3 + 7) x – (2 + 4) x
= 10x – 6x
= 4x
Therefore, 3x – 2x – 4x + 7x = 4x
(iv) 5ab + 2ab – 6ab + ab
The given expression is calculated as below
5ab + 2ab – 6ab + ab = 5ab + 2ab + ab – 6ab
We get,
= 8ab – 6ab
= 2ab
Therefore, 5ab + 2ab – 6ab + ab = 2ab
(v) 8x – 5y – 3x + 10y
The given expression is calculated as below
8x – 5y – 3x + 10y = 8x – 3x + 10y – 5y
= 5x + 5y
Therefore, 8x – 5y – 3x + 10y = 5x + 5y
5. Evaluate:
(i) -7x + 9x + 2x – 2x
(ii) 5ab – 2ab – 8ab + 6ab
(iii) -8a – 3a + 12a + 13a – 6a
(iv) 19abc – 11abc – 12abc + 14abc
Solution:
(i) -7x + 9x + 2x – 2x
The value of given expression is calculated as follows
-7x + 9x + 2x – 2x = 9x + 2x – 7x – 2x
= 11x – 9x
We get,
= 2x
Hence, -7x + 9x + 2x – 2x = 2x
(ii) 5ab – 2ab – 8ab + 6ab
The value of given expression is calculated as follows
5ab – 2ab – 8ab + 6ab = 5ab + 6ab – 2ab – 8ab
We get,
= 11ab – 10ab
= ab
Hence, 5ab – 2ab – 8ab + 6ab = ab
(iii) –8a – 3a + 12a + 13a – 6a
The value of given expression is calculated as follows
-8a – 3a + 12a + 13a – 6a = 12a + 13a – (8a + 3a + 6a)
= 25a – 17a
= 8a
Hence, -8a – 3a + 12a + 13a – 6a = 8a
(iv) 19abc – 11abc – 12abc + 14abc
The value of given expression is calculated as follows
19abc – 11abc – 12abc + 14abc = abc (19 – 11 – 12 + 14)
= abc (33 – 23)
= 10abc
Hence, 19abc – 11abc – 12abc + 14abc = 10abc
6. Subtract the first term from the second:
(i) 4ab, 6ba
(ii) 4.8b, 6.8b
(iii) 3.5abc, 10.5abc
(iv) 3(1 / 2) mn, 8(1 / 2)nm
Solution:
(i) 4ab, 6ba
The subtraction of first term from the second term is calculated as below
6ba – 4ab = 2ab
(ii) 4.8b, 6.8b
The subtraction of first term from the second term is calculated as below
6.8b – 4.8b = 2b
(iii) 3.5abc, 10.5abc
The subtraction of first term from the second term is calculated as below
10.5abc – 3.5abc = 7abc
(iv) 3(1 / 2) mn, 8(1 / 2)nm
The subtraction of first term from the second term is calculated as below
8(1 / 2)nm – 3 (1 / 2) mn = (17 / 2)nm – (7 / 2)mn
We get,
= [(17mn – 7mn) / 2]
= (10 / 2)mn
= 5mn
7. Simplify:
(i) 2a2b2 + 5ab2 + 8a2b2 – 3ab2
(ii) 4a + 3b – 2a – b
(iii) 2xy + 4yz + 5xy + 3yz – 6xy
(iv) ab + 15ab – 11ab – 2ab
(v) 6a2 – 3b2 + 2a2 + 5b2 – 4a2
Solution:
(i) 2a2b2 + 5ab2 + 8a2b2 – 3ab2
The simplified form of the given expression is calculated as follows
2a2b2 + 5ab2 + 8a2b2 – 3ab2 = 2a2b2 + 8a2b2 + 5ab2 – 3ab2
We get,
= 10a2b2 + 2ab2
Therefore, 2a2b2 + 5ab2 + 8a2b2 – 3ab2 = 10a2b2 + 2ab2
(ii) 4a + 3b – 2a – b
The simplified form of the given expression is calculated as follows
4a + 3b – 2a – b = 4a – 2a + 3b – b
= 2a + 2b
Therefore, 4a + 3b – 2a – b = 2a + 2b
(iii) 2xy + 4yz + 5xy + 3yz – 6xy
The simplified form of the given expression is calculated as follows
2xy + 4yz + 5xy + 3yz – 6xy = 2xy + 5xy – 6xy + 4yz + 3yz
= xy + 7yz
Therefore, 2xy + 4yz + 5xy + 3yz – 6xy = xy + 7yz
(iv) ab + 15ab – 11ab – 2ab
The simplified form of the given expression is calculated as follows
ab + 15ab – 11ab – 2ab = 16ab – 13ab
= 3ab
Therefore, ab + 15ab – 11ab – 2ab = 3ab
(v) 6a2 – 3b2 + 2a2 + 5b2 – 4a2
The simplified form of the given expression is calculated as follows
6a2 – 3b2 + 2a2 + 5b2 – 4a2 = 6a2 + 2a2 – 4a2 + 5b2 – 3b2
We get,
= 4a2 + 2b2
Therefore, 6a2 – 3b2 + 2a2 + 5b2 – 4a2 = 4a2 + 2b2
Comments