Algebraic Expressions and Operations on them Class 7 Practice Set 36 Answers Solutions Chapter 8
Question 1
Maharashtra Board Solution
Simplify (3x – 11y) – (17x + 13y) and choose the right
Solution & Step-by-Step Answer:
(A) 7x – 12y (B) -14x – 54y (C) -3(5x + 4y) (D) -2(7x + 12y) Solution: (D) -2(7x + 12y)
Hints:
(3x – 11y) – (17x + 13y) = 3x – 11y – 17x – 13y
= – 14x – 24y
= – 2 × 7x – 2 × 12y
= – 2(7x + 12y)
Question 2
Maharashtra Board Solution
The product of (23x²y³z) and (-15x³yz²) is __ (A) -34x5y4z3 (B) 34x2y3z5 (C) 145x3y2z (D) 170x3y2z3
Solution & Step-by-Step Answer:
(A) -34x5y4z3
Question 3
Maharashtra Board Solution
Solve the following equations: i. ii. 10 = 2y + 5 iii. 5m – 4 = 1 iv. 6x – 1 = 3x + 8 v. 2(x – 4) = 4x + 2 vi. 5(x + 1) = 74
Solution & Step-by-Step Answer:
i.
ii. 10 = 2y + 5
iii. 5m – 4 = 1
iv. 6x – 1 = 3x + 8
v. 2(x – 4) = 4x + 2
vi. 5(x + 1) = 74
Question 4
Maharashtra Board Solution
Rakesh’s age is less than Sania’s age by 5 years. The sum of their ages is 27 years. How old are they?
Solution & Step-by-Step Answer:
Let the age of Rakesh be x years. ∴ Sania’s age = (x + 5) years. According to the given condition, x + (x + 5) = 27 ∴ 2x + 5 = 27 ∴ 2x = 27 – 5 ∴ 2x = 22 ∴ Sania’s age = x + 5 = 11 + 5 = 16 years ∴ The ages of Rakesh and Sania are 11 years and 16 years respectively.
Question 5
Maharashtra Board Solution
When planting a forest, the number of jambhul trees planted was greater than the number of ashoka trees by 60. If there are altogether 200 trees of these two types, how many jambhul trees were planted?
Solution & Step-by-Step Answer:
Let the number of jambhul trees planted be x. ∴ Number of ashoka trees = x – 60 According to the given condition, x + x – 60 = 200 ∴ 2x = 200 + 60 ∴ 2x = 260 ∴ ∴ 130 jambhul trees were planted.
Question 6
Maharashtra Board Solution
Shubhangi has twice as many 20-rupee notes as she has 50-rupee notes. Altogether, she has 2700 rupees. How many 50-rupee notes does she have?
Solution & Step-by-Step Answer:
Let the number of 50-rupee notes with shubhangi be x. ∴ Number of 20-rupee notes = 2x ∴ Total amount with Shubhangi = Number of 50-rupee notes × 50 + Number of 20-rupee notes × 20 = x × 50 + 2x × 20 = 50x + 40x = 90x According to the given condition, 90x = 2700 ∴ ∴ Shubhangi has 30 notes of 50 rupees.
Question 7
Maharashtra Board Solution
virat made twice as many runs as Rohit. The total of their scores is 2 less than a double century. How many runs did each of them make?
Solution & Step-by-Step Answer:
Let the runs made by Rohit be x. ∴ Runs made by Virat = 2x According to the given condition, x + 2x = 200 – 2 ∴ 3x = 198 ∴ ∴ Runs made by Virat = 2x = 2 × 66 = 132 ∴ The runs made by Virat and Rohit are 132 and 66 respectively.
Maharashtra Board Class 7 Maths Chapter 8 Algebraic Expressions and Operations on them Practice Set 36 Intext Questions and Activities
Question 1
Maharashtra Board Solution
Solve the following equations. (Textbook pg. no. 59) i. x + 7 = 4 ii. 4p = 12 iii. m – 5 = 4 iv.
Solution & Step-by-Step Answer:
i. x + 7 = 4 ∴ x + 7 – 7 = 4 – 7 ….(Subtracting 7 from both sides) ∴ x + 0 = -3 ∴ x = -3
ii. 4p = 12
∴ ….(Dividing both sides by 4)
∴ p = 3
iii. m – 5 = 4
∴ m – 5 + 5 = 4 + 5
…. (Adding 5 to both sides)
∴ m + 0 = 9
∴ m = 9
iv.
∴ × 3 = 6 × 3 …. (Multiplying both sides by 3)
∴ t = 18