Question

using suitable identities solve these:

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Answer 1

Step-by-step explanation:

(i) (2y +5) (2y -5)

(2y)2-(5)2

4y2-25

(ii) (2y +3)(2y+ 3)

(2y +3)2

(2y)2 + (3)2 + 2×2y×3

4y2 + 9 + 12y

(iii) (2a-7)(2a-7)

(2a-7)2

(2a)2+ (7)2-2×2a×7

4a2 + 49- 28a

(iv) (2x+y)(2x +y)

(2x + y)2

(2x)2+ (y)2+2×2x×y

4x2 + y2+4xy