Question

if a+b=10,a square+b square=50,then find 4ab Please give the answer​

Answer 1

Answer :-

a² + b² = 60

(a - b)² = 20

Solution :-

i) Finding a² + b²

We know that

(a + b)² = a² + b² + 2ab

Here

• a + b = 10

• ab = 20

By substituting the values

⇒ (10)² = a² + b² + 2(20)

⇒ 100 = a² + b² + 40

⇒ 100 - 40 = a² + b²

⇒ a² + b² = 60

ii) Finding (a - b)²

We know that

(a + b)² = (a - b)² + 4ab

Here

• a + b = 10

• ab = 20

By substituting the values

⇒ (10)² = (a - b)² + 4(20)

⇒ 100 = (a - b)² + 80

⇒ 100 - 80 = (a - b)²

⇒ 20 = (a - b)²

⇒ (a - b)² = 20