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If a+b=5, ab=4 find the value of \( \Large a^{3}+b^{3} \)

A) 60
B) 50
C) 56
D) 65

Correct Answer:




D) 65

Description for Correct answer:
\( \Large a+b=5, ab=4, a^{3}+b^{3}=? \)

Therefore, \( \Large \left(a+b\right)^{3} = a^{3}+b^{3}+3ab \left(a+b\right) \)

\( \Large 5^{3} = a^{3}+b^{3}+3 \times 4 \times 5 \)

\( \Large a^{3}+b^{3}=125 - 60 = 65 \)

Part of solved Factorisation questions and answers : >> Elementary Mathematics >> Factorisation

Comments

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