Page 2 - 8-Math-6 Factorization, Simultaneous Equations

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6.1 BASIC ALGEBRAIC FORMULA

(a+b)2 = a2 +2ab + b2
Example: Evaluate (107)2 by using formula

Solution: (107)2 = (100 + 7)2
= (100)2 + 2(100 x 7) + (7)2
= 10000 + 1400 + 49
= 11449

• (a -b)2 = a2 - 2ab + b2

Example: Using the formula, evaluate (87)2

Solution: (87)2 = (90 - 3)2
= (90)2 - 2(90 x 3) + (3)2
= 8100 - 540 + 9
= 7569

• a2 - b2 = (a+b) (a -b)

Example: Using the formula, evaluate 107 x 93

Solution: 107 x 93 = (100 + 7) (100 - 7)
= (100)2 - (7)2
= 10000 - 49
= 9951

Example: Find the value of x2 + 1 and x4 + 1 when x - 1 =2
x2 x4 x

Solution: Here x- 1 =2
x

 1 2 =2 2
( )  x - x  (Taking square of both the sides)

version: 1.1

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