If 2a + 3b = 8 and ab = 5, then find the value of 4a2 + 9b2.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e 4.
| Understanding/Application |
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2a + 3b = 8 Sq. both side - (2a + 3b)2 = 82 |
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4a2 + 9b2 + 2(2a)(3b) = 64 4a2 + 9b2 + 12(5) = 64 4a2 + 9b2 = 4 |