Question

Use (a + or - b)^2 = (a)^2 +2•a•b + (b)^2

a) 1001 × 999
b) 5.63×5.63+11.26×2.37+2.37×2.37
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Answer 1

★ Your Answer

★ A) 1001 × 999

=) 999× 1001

= (1000-1 × 1000+1)

= (1000)² - (1)

= 1000000 - 1

= 999999. Ans

★B) 5.63 × 5.63 + 11.26 × 2.37 + 2.37 × 2.3711.26 can be written as 2 × 5.63⇒ (5.63)2 + 2 (5.63 × 2.37) + (2.37)2Let here 5.63 = a, 2.37 = bAbove equation is in the form of a2 + 2ab + b2 which is equal to (a + b)2∴ (5.63 + 2.37)2 = (8)2 = 64 Ans