x-y=1 , xy = 56 হলে x+y=কত ?
সমাধান
সঠিক উত্তর: Option B
x - y = 1
xy = 56
(x + y)2= (x - y)2 + 4xy
= 12 + 4 × 56
= 1 + 224
= 225
= 152
x + y = 15
xy = 56
(x + y)2= (x - y)2 + 4xy
= 12 + 4 × 56
= 1 + 224
= 225
= 152
x + y = 15
