Question

If ab = 10 and a2 + b2 = 30, what is the value of
(a + b)^2?

Answer 1

ab=10
a^2+b^2=30
((a+b)^2=a^2+2ab+b^2=a^2+b^2+2*10=30+20=50

Answer 2

Answer: (a + b)² = 50

Explanation:

(a + b)² = (a + b)(a + b)

= a² + ab + ab + b²

So, (a + b)² = a² + b² + 2ab

Then substitute the value of ab and (a² + b²)

(a + b)² = 30 + 2(10)

= 30 + 20

Therefore, (a + b)² = 50