CUET Preparation Today
If (3p - 5m) = 5 and pm = 6, then what is the value of $(9p^2 - 25m^2)$ ? |
$±5\sqrt{385}$ $30\sqrt{10}$ $5\sqrt{385}$ $±30\sqrt{10}$ |
$±5\sqrt{385}$ |
Given = (3p - 5m) = 5 pm = 6 We know that, (a - b)2 = a2 + b2 - 2ab (a2 - b2) = (a - b)(a + b) (a + b)2 = (a - b)2 + 4ab Calculation: = (3p + 5m)2 = (3p - 5m)2 + 4 × 3p × 5m = 25 + 60 × 6 = (3p + 5m) = ±\(\sqrt {385}\) |
