Question

If x² + y² = 4 and x + y = 2 then the value of xy ? ​

Answer 1

Answer:

Step-by-step explanation:

x+y=-4

x=-4-y (call this equation 1)

also xy=2

y=2/x (call this equation 2)

since x =-4-y thus usimg this value of x in equation 2 , we get

y=2/-4-y

-4y-y^2=2 ( cross multiplication)

-y^2-4y=2

or y^2+4y=-2

y^2+4y+2=O

after solving this quad. equation get value of y n then using this value of y get value of x usimg equation 1 then put on this value of x n y in given problem n get the answer ; )

Answer 2

To Find : -

• Values of xy

Identity used:-

• (a+b)² = a²+b²+2ab

Solution : -

Given,

• x² + y² = 4
• x + y = 2

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We have,

x + y = 2

Squaring on both sides :-

→(x + y)² = (2)²

→x² + y² + 2xy = 4

→2xy = 4 - 4

→2xy = 0

→2xy = 0/2

→xy = 0

• Hence, value of xy = 0

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