Question
If [5a - (1/2a)] = 7, then find the value of [25a² +
(1/4a²) - 3]Solution
[5a - (1/2a)] = 7
On squaring both sides,
Or, 25a² + (1/4a²) - 2 × 5a × (1/2a) = 49
Or, 25a² + (1/4a²) - 5 = 49
So, 25a² + (1/4a²) = 54
Required value = 54 - 3 = 51
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