Question

find cube of 998 using expansion formula

plese give full answer​

Answer 1

QUESTION :-

Evaluate the Following using Suitable Identities :- 998³

SOLUTION :-

Using the Identity, $\boxed {\bold {(a - b)^3 = a^3 - b^3 - 3ab\:(a - b)}}$, we get the Value of 998³ as -

$(998)^3 = (1000 - 2)^3$

$\Rightarrow (1000)^3 - 2^3 - 3 \times 1000 \times 2\:(1000 - 2)\\\\\Rightarrow 1,00,00,00,000 - 8 - 6000\:(1000 - 2)\\\\\Rightarrow 1,00,00,00,000 - 8 - 60,00,000 + 12,000\\\\\ = \bold {99,40,11,992}$

VERIFICATION :-

$(998)^3 = 998 \times 998 \times 998 = \bold {99,40,11,992}$

CONCLUSION :-

∴ The Value of 998³ is = 99,40,11,992...