Question

If xy=5 and x square +y square =25 ,then (x+y)square ​

Answer 1

35

Explanation:

`xy = 5 \\ \\ {x}^(2) + {y}^(2) = 25 \\ \\ \because \: {(x + y)}^(2) = {x}^(2) + {y}^(2) + 2xy\\ \\ \therefore {(x + y)}^(2) = 25 + 2 * 5 \\ \\ \therefore {(x + y)}^(2) = 25 + 10 \\ \\ \huge \red{ \boxed{\therefore {(x + y)}^(2) = 35}}`

Answer 2

(x + y)² = 35

Explanation:

The expansion of

(x + y)² = x² + 2xy + y²

= x² + y² + 2xy ← substitute given values

= 25 + 2(5)

= 25 + 10

= 35