Chapter 13 Exponents and Powers Exercise 13.3
Chapter 13 Exponents and Powers Exercise 13.3 Ex 13.3 Class 7 Maths Question 1. Write the following numbers in the e×panded forms: 279404, 3006194, 2806196, 120719, 20068 Solution: (i) 279404 = 2 × 100000 + 7 × 10000 + 9 × 1000 + 4 × 100 + 0 × 10 + 4 = 2 × […]
Chapter 13 Exponents and Powers Exercise 13.2
Chapter 13 Exponents and Powers Exercise 13.2 Question 1. Using laws of exponents, simplify and write the answer in exponential form: Question 2. Simplify and express each of the following in exponential form: Solution: Question 3. Say true or false and justify your answer: (i) 10 × 1011 = 10011 (ii) 23 > 52 (iii) 23 × 32 = […]
Chapter 13 Exponents and Powers Exercise 13.1
Chapter 13 Exponents and Powers Exercise 13.1 Question 1. Find the value of (i) 26 (ii) 93 (iii) 112 (iv) 54 Solution: (i) 26 = 2 × 2 × 2 × 2 × 2 × 2 = 64 (ii) 93 = 9 × 9 × 9 = 729 (iii) 112 = 11 × 11 = 121 (iv) 54 = […]
Chapter 12 Algebraic Expressions
Chapter 12 Algebraic Expressions Very Short Answer Type Question 1. Identify in the given expressions, terms which are not constants. Give their numerical coefficients. (i) 5x – 3 (ii) 11 – 2y2 (iii) 2x – 1 (iv) 4x2y + 3xy2 – 5 Solution: Question 4. Classify the following into monomials, binomial and trinomials. (i) -6 (ii) […]
Chapter 12 Algebraic Expressions Exercise 12.4
Chapter 12 Algebraic Expressions Exercise 12.4 Question 2. Use the given algebraic expression to complete the table of number patterns: S.No. Expression Terms 1st 2nd 3rd 4th 5th … 10th … 100th … (i) 2n – 1 1 3 5 7 9 – 19 – – – (ii) 3n + 2 5 8 11 14 […]
Chapter 12 Algebraic Expressions Exercise 12.3
Chapter 12 Algebraic Expressions Exercise 12.3 Question 2. If p = -2, find the value of: (i) 4p + 7 (ii) -3p2 + 4p + 7 (iii) -2p3 – 3p2 + 4p + 7 Solution: (i) 4p + 7 Putting p = -2, we get 4(-2) + 7 = -8 + 7 = -1 (ii) -3p2 + 4p + […]
Chapter 12 Algebraic Expressions Exercise 12.2
Chapter 12 Algebraic Expressions Exercise 12.2 Question 1. Simplify combining like terms: (i) 21b -32 + 7b- 206 (ii) -z2 + 13z2 -5z + 7z3 – 152 (iii) p – (p – q) – q – (q – p) (iv) 3a – 2b — ab – (a – b + ab) + 3ab + 6 – a […]
Chapter 12 Algebraic Expressions Exercise 12.1
Chapter 12 Algebraic Expressions Exercise 12.1 Question 1. Get the algebraic expressions in the following cases using variables, constants and arithmetic operations: (i) Subtraction of z from y. (ii) One half of the sum of numbers x and y. (iii) The number z multiplied by itself. (iv) One-fourth of the product of numbers p and […]
Chapter 11 Perimeter and Area
Chapter 11 Perimeter and Area Very Short Answer Type Question 1. The side of a square is 2.5 cm. Find its perimeter and area. Solution: Side of the square = 2.5 cm Perimeter = 4 × Side = 4 × 2.5 = 10 cm Area = (side)2 = (4)2 = 16 cm2 Question 2. If the perimeter […]
Chapter 11 Perimeter and Area Exercise 11.4
Chapter 11 Perimeter and Area Exercise 11.4 Question 1. A garden is 90 m long and 75 m broad. A path 5 m wide is to be built outside and around it. Find the area of the path. Also find the area of the garden in hectare. Solution: Given: Length = 90 m Breadth = […]