Question

যদি a + b = √13 এবং a - b = √5 হয়, তা হলে (a² + b²) এর মান হবে - i) 2 ii) 8 iii) 9 iv) 18​

Answer 1

Answer:

Option iii) 9

(a+b)² = a²+b²+2ab

(a-b)² = a²+b²-2ab

Thus,

After Squaring Both Equations

a²+b²+2ab = 13 -- eq1

a²+b²-2ab = 5 -- eq2

Adding Both Equations,

2(a²+b²) = 18

Thus,

a²+b² = 9