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1. x - y = 1; xy = 56 হলে x+y = কত?
- A. 16
- B. 16
- C. 16
- D. 16
Answer: Option B
Explanation:
X - y = 1
xy = 56
(x - y)^2 = x^2 + y^2 - 2xy
1 = x^2 + y^2 - 112
1 + 112 = x^2 + y^2
x^2 + y^2 = 113
(x + y)^2 = 113 + 112
= 225
x + y = 15
xy = 56
(x - y)^2 = x^2 + y^2 - 2xy
1 = x^2 + y^2 - 112
1 + 112 = x^2 + y^2
x^2 + y^2 = 113
(x + y)^2 = 113 + 112
= 225
x + y = 15
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