Question

Using expansion formula find cube of 98

Answer 1

find★

• Using expansion formula cube of 98

solution★

• $\implies(98) { {}^{3} }$

• can we be written as

• $\implies(100 - 2) {}^{3}$

• we know that

• $\implies(a - b) {}^{3} = a {}^{3} - b {}^{3} - 3a {}^{2} b + 3ab {}^{2}$

• comparison

• a=100 and b=2

• $\implies100 {}^{3} - 2 {}^{3} - 3(100) {}^{2}(2) + 3(100)(2) {}^{2}$

• $\implies1000000 - 8 - 60000 + 1200$

• $\implies1001200 - 60008$

• $\implies941 192$

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i hope it helps you