PSEB 7th Class Maths Solutions Chapter 12 Algebraic Expressions Ex 12.1

Punjab State Board PSEB 7th Class Maths Book Solutions Chapter 12 Algebraic Expressions Ex 12.1 Textbook Exercise Questions and Answers.

PSEB Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1

1. Generate algebraic expressions for the following :

(i) The sum of a and b.
(ii) The number z multiplied by itself.
(iii) The product of x and y added to the product of m and n.
(iv) The quotient of p by 5 is multiplied by q.
(v) One half of z added to twice the number t.
(vi) Sum of squares of the number x and z.
(vii) Sum of the numbers x and z is subtracted from their product.
Solution:
(i) a + b
(ii) z²
(iii) xy + mn
(iv) \(\frac{p}{5} q\)
(v) \(2 t+\frac{z}{2}\)
(vi) x² + z²
(vii) xy – (x + y)

2. Separate constant terms and variable terms from the following :
7, xy, \(\frac{3 x^{2}}{2}, \frac{72}{3} z, \frac{-8 z}{3 x^{2}}\)
Solution:
Constant Terms 7, \(\frac {72}{3}\)
Variable Terms xy, \(\frac{3 x^{2}}{2}, \frac{72}{3} z, \frac{-8 z}{3 x^{2}}\)

3. Write the terms and factors for each of the following algebraic expression.
(a) 2x² + 3yz
(b) 15x²y + 3xy²
(c) -7xyz²
(d) 100pq + 10p²q²
(e) xy + 3x²y²
(f) -7x²yz + 3xy²z + 2xyz²
Solution:

Expression	Terms	Factors
(a) 2x2 + 3xy	2x2 3xy	2, x, x 3, x, y
(b) 15x2y + 3xy2	15x2y 3xy2	15, x, x, y 3, x, y, y
(c) -7xyz2	-7xyz2	-7, x, y, z, z
(d) 100pq + 10p2q2	100pq 10p2q2	100, p, q 10, p, p, q, q
(e) xy + 3x2y2	Xy 3x2y2	X, y 3, x, x, y, y
(f) -7x2yz + 3xy2z + 2 xyz2	-7x2yz 3xy2z 2xyz2	-7, x, x, y, z 3, x, y, y, z 2, x, y, z, z

4. Classify the following algebraic expression into monomial, binomial and trinomial.
(a) 7x + 3y
(b) 5 + 2x2y²z
(c) ax + by² + cz²
(d) 3x²y²
(e) 1 + x
(f) 10
(g) \(\frac {3}{2}\)p + \(\frac {7}{6}\)q
Solution:
(a) Binomial
(b) Binomial
(c) Trinomial
(d) Monomial
(e) Binomial
(f) Monomial
(g) Binomial.

5. Write numerical coefficient of each of the following algebraic expression.
(a) 2x
(b) \(\frac {-3}{2}\)xyz
(c) \(\frac {7}{2}\)x²p
(d) -p²q²
(e) -5mn²
Solution:
(a) 2
(b) \(\frac {-3}{2}\)
(c) \(\frac {7}{2}\)
(d) -1
(e) -5

6. State whether the given pairs of terms is of like or unlike terms.
(a) – 3y, \(\frac {7}{8}\)y
(b) – 32, – 32x
(c) 3x²y, 3xy²
(d) 14mn², 14mn²q
(e) 8pq, 32pq²
(f) 10, 15
Solution:
(a) Like
(b) Unlike
(c) unlike
(d) unlike
(e) unlike
(f) like

7. In the following algebraic expressions write the coefficient of :
(a) x in x²y
(b) xyz in 15x²yz
(c) 3pq² in 3p²q²r²
(d) m² in m² + n²
(e) xy in x²y² + 2x + 3
Solution:
(a) xy
(b) 15x
(c) pr²
(d) 1
(e) xy

8. Identify the terms and their factors in the following algebraic expressions by tree diagrams
(a) 12xy + 7x²
(b) p²q² + 3mn² – pqr
(c) 2x²y² + xyz² + zy
(d) \(\frac {3}{2}\)x³ + 2x²y² – 7y³
Solution:
(a)

(b)

(c)

(d)

9. Multiple Choice Questions :

Question (i).
An expression with only one term is called a
(a) Monomial
(b) Binomial
(c) Trinomial
(d) None of these
Answer:
(a) Monomial

Question (ii).
The coefficient of x in 8 – x + y is
(a) -1
(b) 1
(c) 8
(d) 0
Answer:
(a) -1

Question (iii).
Which of the following are like terms ?
(a) 7x, 12y
(b) 15x, 12x
(c) 3xy, 3x
(d) 2y, -2yx
Answer:
(c) 3xy, 3x

Question (iv).
Terms are added to form
(a) Expressions
(b) Variables
(c) Constants
(d) Factors
Answer:
(a) Expressions