## FACTORIZATION – EXERCISE 3.2.5 – Class 9

Factorise: (i) 8y3 – 1 Solution: = (2y)3 – 13 [∵ a3 – b3 = (a – b) (a2 + ab + b2)] = (2y – 1) [(2y)2 + 2y .1 + 12] = (2y – 1) (4y2 + 2y + 1)   (ii) 27x3 – 8 Solution: = (3x)3 – 23 [∵ a3 –… Continue reading FACTORIZATION – EXERCISE 3.2.5 – Class 9

## Factorization – EXERCISE 3.2.2 – Class 9

Factorize the following: (i) 9x2 – 16y2 Solution: = (3x)2 – (4y)2 Using a2 – b2 = (a + b) (a – b) = (3x + 4y) (3x – 4y)   (ii) 5x2 – 7y2 [ Hint : ( 𝟓 )2 = 5 ] Solution: ( 5 x)2 - ( 7 y)2 Using a2 – b2… Continue reading Factorization – EXERCISE 3.2.2 – Class 9

Mathematics

## STATISTICS – EXERCISE 1.5.2 – Class 9

STATISTICS - EXERCISE 1.5.2 – Class 9 Calculate the range and coefficient of range from the following data. a) The heights of 10 children in cm: 122, 144, 154, 101, 168, 118, 155, 133, 160, 140 Solution: Heights of 10 children in cm: 122, 144, 154, 101, 168, 118, 155,133, 160,140. Range: H – L… Continue reading STATISTICS – EXERCISE 1.5.2 – Class 9

## SETS – EXERCISE 1.4.5 – Class 9

If A' = {1, 2, 3, 4}, U = {1, 2, 3, 4, 5, 6, 7, 8}, find A in U and draw Venn diagram Solution:  A' = {5, 6, 7, 8} If U = {x/x € 25, x€N}. A = {x/x € U, x ≤ 15} and B = {x/x € U, 0 <… Continue reading SETS – EXERCISE 1.4.5 – Class 9

## SURDS – EXERCISE – 1.3.4 – Class 9

Find which is larger: (i) 3∛𝟑 and 4∜𝟒 ∛(3×32)                                                        4×424 = ∛27 x ∛3                                                   = ∜256 x ∜4 = ∛81                                                             = ∜1024 = ((81)4)1/12             … Continue reading SURDS – EXERCISE – 1.3.4 – Class 9

## SURDS – EXERCISE 1.3.2 – Class 9

Simplify the following using laws of indices: (i) (16)-0.75 x (64)4/3 (16)-0.75 x (64)4/3                              [16 = 24 ] = (24)-0.75 x (24)4/3                         [64 = 26 ] = 24 x -3/4 x 26 x 4/3 = 2-3 x 28 = 25 = 32   (ii) (0.25)0.5 x (100)-1/2 (0.25)0.5 x (100)-1/2 = (0.25)1/2 x (1/100 )1/2… Continue reading SURDS – EXERCISE 1.3.2 – Class 9