Question

If x + y = 10 and xy = 9, find x2 + y2.​

Answer 1

Answer:

The answer is 82

Step-by-step explanation:

x + y = 10 and xy = 9(given)

To find the value of x^2 + y^2 we have to follow one identity

Step 1 = Let both L.H.S and R.H.S  be whole^2

          That is(x + y)^2 = (10)^2

           (by identity (a + b)^2 = a^2 +2ab +b^2)

Step 2 =

(x + y)^2 = (10)^2

x^2 +2(x)(y) +y^2 = 100

x^2 +y^2 +2xy = 100

x^2 +y^2 +2(9)[as xy = 9] = 100

x^2 +y^2 +18 = 100

x^2 +y^2 = 100 - 18

               = 82

         

Answer 2

Answer:

The answer to this question is 82