ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 8 Algebraic Expressions Ex 8.2

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 8 Algebraic Expressions Ex 8.2

Question 1.
Add:
(i) 7x, -3x
(ii) 6x, -11x
(iii) 5x², -9x²
(iv) 3ab², -5ab²
(v) pq, pq
(vi) 5x³y, x³y
Solution:

Question 2.
Add:
(i) 3x, -5x, 7x
(ii) 7xy, 2xy, -8xy
(iii) -2abc, 3abc, abc
(iv) 3mn, -5mn, 8mn, -4mn
(v) 2x³, 3x³, -4x³, -5x³
Solution:

Question 3.
Simplify the following combining like terms:
(i) 21b – 32 + 7b – 20b
(ii) 12m² – 9m + 5m – 4m² – 7m + 10
(iii) -z² + 13z² – 5z + 7z² – 15z
(iv) 5x²y – 5x² + 3yx² – 3y² + x² – y² + 8xy² – 3y²
(v) p – (p – q) – (q – p) – q
(vi) 3a – 2b – ab – (a – b + ab) + 3ab + b – a
(vii) (3y² + 5y – 4) – (8y – y² – 4)
Solution:

Question 4.
Find the sum of the following algebraic expressions:
(i) 5xy, -7xy, 3x²
(ii) 4x²y, -3xy², -5xy², 5x²y
(iii) -7mn + 5, 12mn + 2, 8mn – 8, -2mn – 3
(iv) a + b – 3, b – a + 3, a – b + 3
(v) 14x + 10y – 12xy – 13, 18 – 7x – 10y + 8xy, 4xy
(vi) 5m – 7n, 3n – 4m + 2, 2m – 3mn – 5
(vii) 3x³ – 5x² + 2x + 1, 3x – 2x² – x³, 2x² – 7x + 9
(viii) 7a² – 5a + 2, 3a² – 7, 2a + 9, 1 + 2a – 5a²
Solution:

Question 5.
Simplify the following:
(i) 2x² + 3y² – 5xy + 5x² – y² + 6xy – 3x²
(ii) 3xy² – 5x²y + 7xy – 8xy² – 4xy + 6x²y
(iii) 5x⁴ – 7x² + 8x – 1 + 3x³ – 9x² + 7 – 3x⁴ + 11x – 2 + 8x²
Solution:

Question 6.
Subtract:
(i) -5y² from y²
(ii) -7xy from -2xy
(iii) a(b – 5) from b(5 – a)
(iv) -m² + 5mn from 4m² – 3mn + 8
(v) 5a² – 7ab + 5b² from 3ab – 2b – 2b²
(vi) 4pq – 5q² – 3p² from 5p² + 3q² – pq
(vii) 7xy + 5x² – 7y² + 3 from 7x² – 8xy + 3y² – 5
(viii) 2x⁴ – 7x² + 5x + 3 from x⁴ – 3x³ – 2x² + 3
Solution:

Question 7.
Subtract p – 2q + r from the sum of 10p – r and 5p + 2q.
Solution:

Question 8.
From the sum of 4 + 3x and 5 – 4x + 2x², subtract the sum of 3x² – 5x and -x² + 2x + 5.
Solution:

Question 9.
What should be added to x² – y² + 2xy to obtain x² + y² + 5xy?
Solution:

Question 10.
What should be subtracted from -7mn + 2m² + 3n² to get m² + 2mn + n²?
Solution:

Question 11.
How much is y⁴ – 12y² + y + 14 greater than 17y³ + 34y² – 51y + 68?
Solution:

Question 12.
How much does 93p² – 55p + 4 exceed 13p³ – 5p² + 17p – 90?
Solution:

Question 13.
What should be taken away from 3x² – 4y² + 5xy + 20 to obtain -x² – y² + 6xy + 20?
Solution:

Question 14.
From the sum of 2y² + 3yz, -y² – yz – z² and yz + 2z², subtract the sum of 3y² – z² and -y² + yz + z².
Solution:

ML Aggarwal Class 7 Solutions for ICSE Maths