If 2p + 5q = 12 and pq = 3, find the value of 4p2 + 25 q2. |
64 24 84 44 |
84 |
If 2p + 5q = 12 pq = 3 Find the value of 4p2 + 25 q2 ( a + b )2 = a2 + b2 + 2ab 2p + 5q = 12 Squaring on both sides, 4p2 + 25p2 + 2 × 2p × 5q = 144 4p2 + 25p2 + 20pq = 144 4p2 + 25p2 = 144 - 20pq 4p2 + 25p2 = 144 - 20 × 3 4p2 + 25p2 = 84 |