MATHS FLASH CARDS: Using suitable identity evaluate the following:
98³

Question

Using suitable identity evaluate the following:
98³

GN Tutorials · Accepted Answer

(98)³ = (100 - 2)³
          = (100 - 2)³is of the form (a - b)³
(a - b)³ = a³ - 3a²b + 3ab² - b³
So, 
(100 - 2)³ = 100³ - (3 × 100² × 2) + (3 × 100 × 2²) - 2³
= 1,000,000 - 60,000 + 1200 - 8 
= 9,41,192

MATHS FLASH CARDS

Using suitable identity evaluate the following: 98³

(98)³ = (100 - 2)³ = (100 - 2)³is of the form (a - b)³ (a - b)³ = a³ - 3a²b + 3ab² - b³ So, (100 - 2)³ = 100³ - (3 × 100² × 2) + (3 × 100 × 2²) - 2³ = 1,000,000 - 60,000 + 1200 - 8 = 9,41,192

Author