Q4 of 59 Page 162

Expand:

(i) (2t + 5)(2t – 5);


(ii) (xy + 8)(xy – 8);


(iii) (2x + 3y)(2x – 3y).

(i) We use the form (a + b)(a-b) = a2 - b2


⇒ (2t + 5)(2t – 5) = 4t2-25


(ii) We use the form (a + b)(a-b) = a2 - b2


⇒(xy + 8)(xy – 8) = x2y2-64


(iii) We use the form (a + b)(a-b) = a2 - b2


⇒(2x + 3y)(2x – 3y) = 4x2-9y2


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Take away 8x – 7y – 8p + 10q from 10x + 10y – 7p + 9q.

 3

Expand:

(i) (4x + 3)2


(ii) (x + 2y)2


(iii)


(iv)

5

Expand:

(n – 1)(n + 1)(n2 + 1)

 5

Expand: