Question

find the value of
${x}^{2} + {y}^{2}$
if x+y=10
xy=15
​

Answer 1

Answer:

Given = x + y= 10

X- y = 15

Now, squaring eq 1 & 2

X² + Y ² + 2XY = 100

X² + Y² - 2XY = 225

ADDING BOTH OF THEM

2( X² + Y²) = 325

HENCE, X² + Y² = 325/2

Answer 2

Step-by-step explanation:

$x + y = 10 \\ xy = 15 \\ according \: to \: the \: question \\ x + y = 10 \\ = > {(x +y )}^{2} = 10 \\ = > {x}^{2} + 2xy + {y}^{2} = 10 \\ = > {x}^{2} + {y}^{2} + 2xy = 10 \\ = > {x}^{2} + {y}^{2} + 2(15) = 10 \\ = > {x}^{2} + {y}^{2} + 30 = 10 \\ = > {x}^{2} + {y}^{2} = \frac{10}{30} \\ = \frac{1}{3}$