If $x^2 + 4y^2 = 40$, xy = 6, and x > 2y, then the value of x - 2y is : |
1 3 2 4 |
4 |
If $x^2 + 4y^2 = 40$, xy = 6, and x > 2y, then the value of x - 2y is = ? We know, a² + b² = (a - b)² + 2ab According to question, x2 + 4y2 = (x - 2y)2 + 4xy = (x - 2y)2 = 40 - 4(6) = (x - 2y)2 = (16 = x - 2y = 4 |