NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1 are part of NCERT Solutions for Class 7 Maths. Here we have given NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1.

- Algebraic Expressions Class 7 Ex 12.2
- Algebraic Expressions Class 7 Ex 12.3
- Algebraic Expressions Class 7 Ex 12.4
- Algebraic Expressions Class 7 MCQ

Board |
CBSE |

Textbook |
NCERT |

Class |
Class 7 |

Subject |
Maths |

Chapter |
Chapter 12 |

Chapter Name |
Algebraic Expressions |

Exercise |
Ex 12.1 |

Number of Questions Solved |
7 |

Category |
NCERT Solutions |

## NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1

**Question 1.**

Get the algebraic expressions in the following cases using variables, constants, and arithmetic operations.

(i) Subtraction of z from y.

Solution:

y – z

(ii) One-half of the sum of numbers x and y.

Solution:

\(\frac{1}{2}\) (x -y)

(iii) The number z multiplied by itself.

Solution:

z × z i.e., z^{2}

(iv) One-fourth of the product of numbers p and q.

Solution:

\(\frac{1}{4}\) pq

(v) Numbers x and y both squared and added.

Solution:

x^{2} + y^{2}

(vi) Number 5 added to three times the product of numbers m and n.

Solution:

3mn + 5

(vii) Product of numbers y and z subtracted from 10.

Solution:

10 – yz

(viii) Sum of numbers a and 6 subtracted from their product.

Solution:

ab – (a + b)

**Question 2.**

**(i)** Identify the terms and their factors in the following expressions. Show the terms and factors by tree diagrams :

**(a)** x – 3

**(b)** 1 + x + x^{2}

**(c)** y – y^{3}

**(d)** 5xy^{2} + 7x^{2}y

**(e)** -ab + 2b^{2} -3a^{2}

**(ii)** Identify terms and factors in the expressions given below :

**(a)** – 4x + 5

**(b)** – 4x + 5y

**(c)** 5y + 3y^{2}

**(d)** xy + 2x^{2}y^{2}

**(e)** pq + q

**(f)** 1.2 ab -2.4 b + 3.6 a

**(g)** \(\frac { 3 }{ 4 } \) x + \(\frac { 1 }{ 4 } \)

**(h)** 0.1 p^{2} + 0.2 q^{2}

**Solution:
**

**Question 3.**

Identify the numerical coefficients of terms (other than constants) in the following expressions :

- 5 – 3t
^{2} - 1 + t + t
^{2}+ t^{3} - x + 2xy + 3y
- 100m + 1000n
- -p
^{2}q^{2}+ 7pq - 1.2 a + 0.8 b
- 3.14 r
^{2} - 2 (l + b)
- 0.1 y + 0.01 y
^{2}.

**Solution:
**

**Question 4.**

**(a)** Identify terms which contain x and give the coefficient of x.

- y
^{2}x + y - 13y
^{2}– 8yx - x + y + 2
- 5 + z + zx
- 1 + x + xy
- 12xy
^{2}+ 25 - 7x + xy
^{2}.

**(b)** Identify terms which contain y^{2} and give the coefficient of y^{2}.

- 8 – xy
^{2} - 5y
^{2}+ 7x - 2x
^{2}y – 15xy^{2}+ 7y^{2}

**Solution:
**

**Question 5.**

Classify into monomials, binomials and trinomials.

- 4y – 7z
- y
^{2} - x + y – xy
- 100
- ab – a – b
- 5 – 3t
- 4p
^{2}q – 4pq^{2} - 7mn
- z
^{2}– 3z + 8 a^{2}+ b^{2} - z
^{2}+ z - 1 + x+ x
^{2}

**Solution:
**We know that an algebraic expression containing only one term is called a monomial. So, the monomials are : (ii), (iv), and (viii).

We know that an algebraic expression containing two terms is called a binomial. So, the binomials are : (i), (vi), (vii), (x) and (xi).

We know that an algebraic expression containing three terms is called a trinomial. So, the trinomial are : (iii), (v), (ix) and (xii).

Question 6.

State whether a given pair of terms is of like or unlike terms :

(i) 1, 100

Solution:

Like

(ii) -7x, \(\frac{5}{2}\)x

Solution:

Like

(iii) – 29x, – 29y

Solution:

Unlike

(iv)14xy, 42yx

Solution:

Like

(v) 4m^{2}p, 4mp^{2}

Answer:

Unlike

(vi) 12xz, 12x^{2}z^{2}

Solution:

Unlike

**(i) 4y – 7z.**

This expression is a binomial because it contains two terms: 4y and – Iz.

**(ii) y ^{2}.**

This expression is a monomial because it contains only one term: y

^{2}

**(iii) x + y – xy.**

This expression is a trinomial because it contains three terms: x, y, and – xy.

**(iv) 100.**

This expression is a monomial because it contains only one term: 100

**(v) ab – a – b.**

This expression is a trinomial because it contains three terms: ab, -a, and -b

**(vi) 5 – 3t.**

This expression is a binomial because it contains two terms : 5 and – 31.

**(vii) 4p**

^{2}q – 4pq^{2}.This expression is a binomial because it contains two terms: 4p

^{2}q and – 4pq

^{2}.

**(viii) 7mn.**

This expression is a monomial because it contains only one term : 7mn.

**(ix) z**

^{2}– 3z + 8.This expression is a trinomial because it contains three terms : z

^{2}, – 3z and 8.

**(x) a**

^{2}+ b^{2}.This expression is a binomial because it contains two terms: a

^{2}and b

^{2}.

**(xi) z**

^{2}+ z.This expression is a binomial because it contains two terms : z

^{2}and z.

**(xii) 1 + x + x**

^{2}.This expression is a trinomial because it contains three terms: 1, x, and x

^{2}.

**Question 6.**

State whether a given pair of terms is of like or unlike terms :

(i) 1, 100

Solution:

Like

(ii) -7x, \(\frac{5}{2}\)x

Solution:

Like

(iii) – 29x, – 29y

Solution:

Unlike

(iv)14xy, 42yx

Solution:

Like

(v) 4m^{2}p, 4mp^{2}

Answer:

Unlike

(vi) 12xz, 12x^{2}z^{2}

Solution:

Unlike

**Question 7.**

Identify like terms in the following :

**Solution:
**

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