Question

please answer this question quickly​

Answer 1

Answer:

x+y=10

squaring both sides

(x+y)²= 10²

x²+y²+2xy=100

68+2xy=100

2xy=100-68

2xy=32

xy=32÷2

xy=16

Answer 2

Question :-

If x + y = 10 and x² + y² = 68. Then xy = ?

Answer :-

The value of xy is 16.

Step-by-step explanation:

To Find :-

• The value of xy.

Given that,

• x + y = 10
• x² + y² = 68.

★ Solution

⇒ x + y = 10

By squaring each side

⇒ (x + y)² = (10)²

⇒ (x + y)² = 100

Using the algebraic identity of [(x+y)² = x²+y²+2xy], We get.

⇒ x² + y² + 2xy = 100

As given per question, [x² + y² = 68],

⇒ 68 + 2xy = 100

Transposing 68 to R.H.S,

⇒ 2xy = 100 - 68

⇒ 2xy = 32

⇒ xy = 32/2

⇒ xy = 16

Hence, The value of xy is 16.

______________________________

V E R I F I C A T I O N :-

• (x + y)² = (10)²

⇒ (x + y)² = (10)²

⇒ (x + y)² = 100

⇒ x² + y² + 2xy = 100

⇒ 68 + 2*16 = 100

⇒ 68 + 32 = 100

⇒ 100 = 100

L.H.S = R.H.S

Hence, Verified!