Question

If x+y=7and xy=12 find value of (x²-xy+y²)​

Answer 1

${\boxed{\underline{\tt{ \orange{Required \: \: answer \: \: is \: \: as \: \: follows:-}}}}}$

★GIVEN:-

• $\sf{x + y = 7 }$

• $\sf{xy = 12 }$

★TO FIND :-

• $\sf{x^2 -xy + y^2 }$

★FORMULA USED:-

• $\sf{ {(x + y)}^{2} = {x}^{2} + {y}^{2} + 2xy}$

★SOLUTION:-

Squaring (x + y)

$\tt{ {(x + y)}^{2} = {x}^{2} + {y}^{2} + 2xy}$

$\tt{ {7}^{2} = {x}^{2} + {y}^{2} + 2 \times 12}$

$\tt{ {x}^{2} + {y}^{2} =49 - 24 }$

$\tt{ {x}^{2} + {y}^{2} = \pink{25} }$

Now, We will find the value of

x^2 - xy + y^2

x^2 + y^2 can be written as 25 as proved above.

$: \longrightarrow \tt{ {x}^{2} + {y}^{2} - xy = 25 - 24}$

$: \longrightarrow { \boxed{ \underline{ \purple{\tt{ {x}^{2} + {y}^{2} - xy = 1}}}}}$

Hence, the value is 1.

Answer 2

Answer:

x+y=7

3+4=7

and

Xy=12

3×4=12

value of (x²-xy+y²)

x=3

y=4

=(3²-3×4+4²)

=(9-12+16)

=(9-28)

=(-19)