**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:**

= ½ (x + y)

= (x + y)/2

**(iii) The number z multiplied by itself.**

**Solution:**

= z × z

= z^{2}

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

**Solution:**

= ¼ (p × q)

= pq/4

**(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 – (y × z)

= 10 – yz

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

**Solution:**

= (a × b) – (a + b)

= ab – (a + b)

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

**(a) x – 3**

**Solution:**

Expression: x – 3

Terms: x, -3

Factors: x; -3

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

**Solution:**

Expression: 1 + x + x^{2}

Terms: 1, x, x^{2}

Factors: 1; x; x,x

**(c) y – y ^{3}**

**Solution:**

Expression: y – y^{3}

Terms: y, -y^{3}

Factors: y; -y, -y, -y

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

**Solution:**

Expression: 5xy^{2} + 7x^{2}y

Terms: 5xy^{2}, 7x^{2}y

Factors: 5, x, y, y; 7, x, x, y

**(e) – ab + 2b ^{2} – 3a^{2}**

**Solution:**

Expression: -ab + 2b^{2} – 3a^{2}

Terms: -ab, 2b^{2}, -3a^{2}

Factors: -a, b; 2, b, b; -3, a, a

**(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) ¾ x + ¼**

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

**Solution:**

Expressions are defined as, numbers, symbols, and operators (such as +. –, ×, and ÷) grouped together which show the value of something.

In an algebraic expression, a term is either a single number or variable, or numbers and variables are multiplied together. Terms are separated by + or – signs or sometimes by division.

Sl.No. | Expression | Terms | Factors |

(a) | – 4x + 5 | -4x 5 | -4, x 5 |

(b) | – 4x + 5y | -4x 5y | -4, x 5, y |

(c) | 5y + 3y^{2} | 5y 3y^{2} | 5, y 3, y, y |

(d) | xy + 2x^{2}y^{2} | xy 2x^{2}y^{2} | x, y 2, x, x, y, y |

(e) | pq + q | pq q | P, q Q |

(f) | 1.2 ab – 2.4 b + 3.6 a | 1.2ab -2.4b 3.6a | 1.2, a, b -2.4, b 3.6, a |

(g) | ¾ x + ¼ | ¾ x ¼ | ¾, x ¼ |

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

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

**(i) 5 – 3t ^{2} **

**(ii) 1 + t + t ^{2} + t^{3} **

**(iii) x + 2xy + 3y**

**(iv) 100m + 1000n**

**(v) – p ^{2}q^{2} + 7pq**

**(vi) 1.2 a + 0.8 b**

**(vii) 3.14 r ^{2} **

**(viii) 2 (l + b)**

**(ix) 0.1 y + 0.01 y ^{2}**

**Solution:**

Sl.No. | Expression | Terms | Coefficients |

(i) | 5 – 3t^{2} | – 3t^{2} | -3 |

(ii) | 1 + t + t^{2} + t^{3} | t t^{2} t^{3} | 1 1 1 |

(iii) | x + 2xy + 3y | x 2xy 3y | 1 2 3 |

(iv) | 100m + 1000n | 100m 1000n | 100 1000 |

(v) | – p^{2}q^{2} + 7pq | -p^{2}q^{2} 7pq | -1 7 |

(vi) | 1.2 a + 0.8 b | 1.2a 0.8b | 1.2 0.8 |

(vii) | 3.14 r^{2} | 3.14^{2} | 3.14 |

(viii) | 2 (l + b) | 2l 2b | 2 2 |

(ix) | 0.1 y + 0.01 y^{2} | 0.1y 0.01y^{2} | 0.1 0.01 |

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

**(i) y ^{2}x + y **

**(ii) 13y ^{2} – 8yx **

**(iii) x + y + 2**

**(iv) 5 + z + zx **

**(v) 1 + x + xy **

**(vi) 12xy ^{2} + 25**

**(vii) 7x + xy ^{2}**

**Solution:**

Sl.No. | Expression | Terms | Coefficient of x |

(i) | y^{2}x + y | y^{2}x | y^{2} |

(ii) | 13y^{2} – 8yx | – 8yx | -8y |

(iii) | x + y + 2 | x | 1 |

(iv) | 5 + z + zx | x zx | 1 z |

(v) | 1 + x + xy | xy | y |

(vi) | 12xy^{2} + 25 | 12xy^{2} | 12y^{2} |

(vii) | 7x + xy^{2} | 7x xy^{2} | 7 y^{2} |

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

**(i) 8 – xy ^{2} **

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

**(iii) 2x ^{2}y – 15xy^{2} + 7y^{2}**

**Solution:**

Sl.No. | Expression | Terms | Coefficient of y^{2} |

(i) | 8 – xy^{2} | – xy^{2} | – x |

(ii) | 5y^{2} + 7x | 5y^{2} | 5 |

(iii) | 2x^{2}y – 15xy^{2} + 7y^{2} | – 15xy^{2} 7y^{2} | – 15x 7 |

**5. Classify into monomials, binomials and trinomials.**

NOTE:

Monomial: An expression with only one term is called a monomial.

Binomial: An expression that contains two unlike terms is called a binomial.

Trinomial: An expression that contains three terms is called a trinomial.

**(i) 4y – 7z**

**Solution:**

Binomial.

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

**Solution:**

Monomial.

**(iii) x + y – xy**

**Solution:**

Trinomial.

**(iv) 100**

**Solution:**

Monomial.

**(v) ab – a – b**

**Solution:**

Trinomial.

**(vi) 5 – 3t**

**Solution:**

Binomial.

**(vii) 4p ^{2}q – 4pq^{2}**

**Solution:**

Binomial.

**(viii) 7mn**

**Solution:**

Monomial.

**(ix) z ^{2} – 3z + 8**

**Solution:**

Trinomial.

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

**Solution:**

Binomial.

**(xi) z ^{2} + z**

**Solution:**

Binomial.

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

**Solution:**

Trinomial.

**6. State whether a given pair of terms is of like or unlike terms.**

**Like term: **When term have the same algebraic factors, they are like terms.

**Unlike term:** The terms have different algebraic factors, they are unlike terms.

**(i) 1, 100**

**Solution:**

Like term.

**(ii) –7x, (5/2)x**

**Solution:**

Like term.

**(iii) – 29x, – 29y**

**Solution:**

Unlike terms.

**(iv) 14xy, 42yx**

**Solution:**

Like term.

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

**Solution:**

Unlike terms.

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

**Solution:**

Unlike terms.

**7. Identify like terms in the following:**

**(a) – xy ^{2}, – 4yx^{2}, 8x^{2}, 2xy^{2}, 7y, – 11x^{2}, – 100x, – 11yx, 20x^{2}y, – 6x^{2}, y, 2xy, 3x**

**Solution:**

When term have the same algebraic factors, they are like terms.

They are,

– xy^{2}, 2xy^{2}

– 4yx^{2}, 20x^{2}y

8x^{2}, – 11x^{2}, – 6x^{2}

7y, y

– 100x, 3x

– 11yx, 2xy

**(b) 10pq, 7p, 8q, – p ^{2}q^{2}, – 7qp, – 100q, – 23, 12q^{2}p^{2}, – 5p^{2}, 41, 2405p, 78qp,13p^{2}q, qp^{2}, 701p^{2}**

**Solution:**

When term have the same algebraic factors, they are like terms.

They are,

10pq, – 7qp,

78qp7p, 2405p8q,

– 100q– p^{2}q^{2}, 12q^{2}p^{2}– 23,

41– 5p^{2},701p^{2}13p^{2}q, qp^{2}

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