The Fancy Maths
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The Fancy Maths blog helps the students who want to become an expert in mathematics subject. If you want to clear your concept in mathematics or if you want to learn the techniques to solve different kind of examples, my blog definitely help you to learn mathematics. On my blog, you get different courses which starts from class 9 and up to class 12. We provide chapter wise formula sheet,..
The Fancy Maths
9M ago
Class 8:Maths : Expansion formulae :Practice Set 5.2
Question 1.
Expand:
(1). (k + 4)³
(2). (7x + 8y)³
(3). (7x + m)³
(4). (52)³
(5). (101)³
(6). (x+1x)3
(7). (2m+15)3
(8). (5xy+y5x)3
Solution:
(1). Here, a = k and b = 4
(k + 4)³ = (k)³ + 3(k)² (4) + 3(k)(4)² + (4)³
…[∵ (a + b)³ = a³ + 3a²b + 3ab² + b³]
= k³ + 12k² + 3(k)(16) + 64
= k³ + 12k² + 48k + 64
(2). Here, a = 7x and b = 8y
(7x + 8y)³
= (7x)³ + 3(7x)² (8y) + 3(7x) (8y)² + (8y)³
…[∵ (a + b)³ = a³ + 3a²b + 3ab² + b³]
= 343x³ + 3(49x²)(8y) + 3(7x)(64y²) + 512y³
= 343x³ + 1176x²y + 1344xy² + 512y³
(3). Here, a = 7 and ..read more
The Fancy Maths
9M ago
Class 8:Maths : Expansion formulae :Practice Set 5.1
Practice Set 5.1
QUE (1) Expand.
(1) (a +2)(a - 1) (2) (m - 4)(m + 6)
(3) (p + 8)(p -3) (4) (13 + x)(13 - x)
(5) (3x + 4y)(3x + 5y) (6) (9x - 5t)(9x + 3t)
(7). (m+23)(m−73)
(8).&nbs ..read more
The Fancy Maths
9M ago
class 8: maths : Indices and Cube root :Practice Set :3.3
Practice Set :3.3
1. Find the cube roots of the following numbers.
(1) 8000
(2) 729
(3) 343
(4) -512
(5) -2744
(6) 32768
ANSWER :
i. 8000
= 2 × 2 × 2 × 10 × 10 × 10
= (2 × 10) × (2 × 10) × (2 × 10)
= (2 × 10)³
= 20³
ii. 729
= (3 × 3) × (3 × 3) × (3 × 3)
= (3 × 3)³
= 9³
iii. 343
= 7 × 7 × 7
= 7³
iv. -512
= 2 × 2 × 2 × 4 × 4 × 4
= (2 × 4) × (2 × 4) × (2 × 4)
= (2 × 4)³
= 8³
∴ – 512 = (- 8) × (- 8) × (- 8)
= (-8)³
v. -2744
= 2 × 2 × 2 × 7 × 7 × 7
= (2 × 7) × (2 × 7) × (2 × 7)
= (2 × 7)³
= 14³
∴ -27 ..read more
The Fancy Maths
9M ago
class 8: maths : Indices and Cube root :Practice Set :3.2
Practice Set :3.2
1. Complete the following table.
S.No.
Number
Power of the root
Root of the power
1.
(225)32
Cube of square root of 225
Square root of cube of 225
2.
(45)45
3.
(81)67
4.
(100)410
5.
(21)37
ANSWER :
S.No.
Number
Power of the root
Root of the power
1.
(225)32
Cube of square root of 225
Square root of cube of 225
2.
(45)45
4th power of 5th root of 45
5th root of 4th power of 45
3.
(81)67
6th power of 7th root of 81
7th root of 6th power of 81
4.
(100)410
4th power of 10th ro ..read more
The Fancy Maths
9M ago
class 8: maths : Indices and Cube root :Practics Set :3.1
1. Express the following numbers in index form.
(1) Fifth root of 13
(2) Sixth root of 9
(3) Square root of 256
(4) Cube root of 17
(5) Eighth root of 100
(6) Seventh root of 30
ANSWER :
i. (13)15
ii. (9)16
iii. (256)12
iv. (17)13
v. (100)18
vi. (30)17
2. Write in the form ‘nth root of a’ in each of the following numbers.
i. (81)14
ii. (49)12
iii. (15)15
iv. (512)19
v. (100)119
vi. (6)17
ANSWER :
i. Fourth root of 81.
ii. S ..read more
The Fancy Maths
9M ago
class 8 : maths :Parallel lines and transversals : Practice set 2.3 ..read more
The Fancy Maths
9M ago
class 8 : maths :Parallel lines and transversals : Practice set 2.2 ..read more