Question

11. If xy = 7. then x-2y - 5 =
(1) (x + 2)(1-y)
(3) (x+2)(1+y)
(2) (x-2)(1-Y)
(4) (x-2)(y -1)​

Answer 1

Answer:

$x - 2y = 5 \\ xy = 7 \\ x = 7 \div y \\ 7 \div y - 2y = 5 \\ 7 - 2 {y}^{2} = 5y \\ 2 {y}^{2} + 5y - 7 = 0 \\ 2 {y}^{2} + (7 - 2)y - 7 = 0 \\ 2 {y}^{2} + 7y - 2y - 7 = 0 \\ y(2y + 7) - 1(2y + 7) \\ (2y + 7)(y - 1)$

Answer 2

Answer:

1

Step-by-step explanation:

x - 2y - 5 = x-2(7/x) - 5

= (x² - 14 - 5x)/x

= (x² +2x-7x - 14)/x

= (x+2)(x-7)/x

= (x+2)(x-xy)/x

= (x+2)(1-y)