Simplify: (2 marks)
${(x y + y z)}^{2} - {(x y - y z)}^{2}$

Open in App

Solution

Using the identity,
${(a + b)}^{2} = a^{2} + b^{2} + 2 a b,$

we get,
${(x y + y z)}^{2} = x^{2} y^{2} + y^{2} z^{2} + 2 x z y^{2} . . . (1)$
(0.5 marks)

Using the identity,
${(a - b)}^{2} = a^{2} + b^{2} - 2 a b$

we get,
${(x y - y z)}^{2} = x^{2} y^{2} + y^{2} z^{2} - 2 x z y^{2} . . . (2)$
(0.5 marks)
Subtracting (2) from (1), we get

$(x^{2} y^{2} + y^{2} z^{2} + 2 x z y^{2}) - (x^{2} y^{2} + y^{2} z^{2} - 2 x z y^{2})$
$= 2 x z y^{2} + 2 x z y^{2}$
$= 4 x y^{2} z$ (1 mark)

Suggest Corrections

Similar questions

Write the degree of each polynomial given below:

(i) $x y + 7 z$ (ii) $x^{2} - 6 x^{3} + 8$

(iii) $y - 6 y^{2} + 5 y^{8}$ (iv) $x y z - 3$

(v) $x y + y z^{2} - z x^{3}$ (vi) $x^{5} y^{7} - 8 x^{3} y^{8} + 10 x^{4} y^{4} z^{4}$

(x y + y z)^{2} - (x y - y z)^{2}

Simplify: ${(x y + y z)}^{2}$ - ${(x y - y z)}^{2}$

(x y + y z)^{2} - 2 x^{2} y^{2} z .

x = - 1, y = 1

z = 2

(x y + y z)^{2} - 2 x^{2} y^{2} z

x = - 1, y = 1

z = 2

Join BYJU'S Learning Program