Q23.Find the value of a^3 − 27b^3 + 45ab + 125, when a = 3b − 5.
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Answer:
Maybe the value is wrong
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Step-by-step explanation:
a³ − 27b³ + 45ab + 125
a = 3b - 5
putting the value of a in the equation
(3b - 5)³ - 27b³ + 45ab + 125
Using identify (a − b)³ = a³ − b³− 3a b ( a − b )
[(3b)³ - (5)³ - 3×3b×5 (3b - 5)] - 27b³ + 45ab + 125
[27a³ - 135 - 45b(3b - 5)] - 27b³ + 45ab + 125
27a³ - 135 - 135b² + 225b - 27b³ + 45ab + 125
27a³ - 27b³ - 135b² + 45ab + 10
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