Question

LES 6. Find the value of each product for x = -1, y = -2, z = 1
(a) x² (1+ y2 -2xy)
(b) 3xy(x2+y2+4)
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Answer 1

Answer:

Step-by-step explanation:

The factor of 1−x  2 −2xy−y  2

Rearranging the terms

⇒ 1−(x  2  +2xy+y  2  )

⇒ −1(x+y)  2

 [∵ (x+y)  2

=x  2  +2xy+y  2  ]

⇒ (1−(x+y)  2  )

⇒ (1)  2

=(x+y)  2

 [∵(1)  2 =1]

Using a  2  −b  2

=(a+b)(a−b)

⇒ (1−(x+y))(1+(x+y))

⇒ (1−x−y)(1+x+y) - solution