Question

5. Find the 408 x 392 by expres these a difference of two squares
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Answer 1

Step-by-step explanation:

391 × 409

= (400 – 9)(400 + 9)

[∵ a2 – b2 = (a – b)(a + b), here taking a = 400, b = 9]

= (400)2 – 92

ii. (4x + 3y)(2x – 3y)

= (3x + x + 3y)(3x – x – 3y)

= (3x + x + 3y)(3x – (x + 3y))

[∵ a2 – b2 = (a – b)(a + b), Here taking a = 3x, b = x + 3y]

= (3x)2 – (x + 3y)2

iii. x

= x.1

[∵ a2 – b2 = (a – b)(a + b), here taking

]