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If a3 + b3 = 152 and a + b = 8, then what is the value of ab?
- A2
- B11
- C-10
- D15
Answer not set
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CCommunity
Given a + b = 8, Cubing both sides
⇒ (a + b)3 = a3 + b3 + 3ab (a + b) ,
Using given data
⇒ 83 = 152 + 3ab × (8)
⇒ (512 – 152)/24 = ab
⇒ ab = 15
∴ the value of ab is 15
⇒ (a + b)3 = a3 + b3 + 3ab (a + b) ,
Using given data
⇒ 83 = 152 + 3ab × (8)
⇒ (512 – 152)/24 = ab
⇒ ab = 15
∴ the value of ab is 15