Question

If x + y = 15 and xy = 17, find the value of x ^2+ y^2
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Answer 1

Answer:

ɢɪᴠᴇɴ , ( x - ʏ ) = 2 ᴀɴᴅ xʏ = 15

ɴᴏᴡ ,

x^2 + ʏ^2

= ( x - ʏ )^2 + 2xʏ

= 2^2 + 2 × 15

= 4 + 30

= 34

sᴏ , ᴛʜᴇ ᴠᴀʟᴜᴇ ᴏғ ( x^2 + ʏ^2 ) ɪs 34

Answer 2

EXPLANATION.

GIVEN

=> x + y = 15 .....(1)

=> xy = 17 ......(2)

To find value of [ x^2 + y^2 ]

=> From equation (1) and (2)

we get,

=> Formula of [ x^2 + y^2 ]

=> ( x + y) ^2 - 2xy

put the value of equation (1) and (2) in formula.

=> ( 15 ) ^2 - 2 X 17

=> 225 - 34

=> 191

Therefore,

Value of [ x^2 + y^2 ] = 191

More information.

1) = Formula of [ x + y ]^2

=> x^2 + y^2 + 2xy

2) = Formula of [ x - y ]^2

=> x^2 + y^2 - 2xy

3) = Formula of [ x^2 + y^2 ]

=> ( x + y ) ^2 - 2xy

4) = Formula of [ x^2 - y^2 ]

=> ( x - y) ^2 + 2xy