X : Y = 2 : 7
7X = 2Y
Y = 3.5X
..........................
1) XY = 14
X * 3.5X = 14
3..5X^2 = 14
X^2 = 4
X = + 2 ---> Y = 3.5 * 2 = 7
X = - 2 ---> Y = - 7
.................................
2) XY = 56
3.5X^2 = 56
X^2 = 16
X = + 4 ----> Y = 14
X = - 4 ----> Y = - 14