Question

x-y=9 ,xy=15 then what is value of x^2+y^2=?​

Answer 1

Answer:

here is the ans ............

Answer 2

Answer:

The value of ${x}^{2} + {y}^{2}$ is 111.

Step-by-step explanation:

Given,

$x - y = 9 \\ xy = 15$

Here we want to find value of

${x}^{2} + {y}^{2}$

We know,

${a}^{2} + {b}^{2} = {(a - b)}^{2} + 2ab$

So,

${x}^{2} + {y}^{2} \\ = {(x - y)}^{2} + 2xy \\ = {9}^{2} + 2 \times 15 \\ = 81 + 30 \\ = 111$

This is a problem of Algebra.

Some important Algebra formulas.

(a + b)² = a² + 2ab + b²

(a − b)² = a² − 2ab − b²

(a + b)³ = a³ + 3a²b + 3ab² + b³

(a - b)³ = a³ - 3a²b + 3ab² - b³

a³ + b³ = (a + b)³ − 3ab(a + b)

a³ - b³ = (a -b)³ + 3ab(a - b)

a² − b² = (a + b)(a − b)

a² + b² = (a + b)² − 2ab

a² + b² = (a − b)² + 2ab

a³ − b³ = (a − b)(a² + ab + b²)

a³ + b³ = (a + b)(a² − ab + b²)

Know more about Algebra,

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2) https://brainly.in/question/1169549