Factories:

100 – (x – 5)2

Given,


100 – (x – 5)2


By using the formula a2 – b2 = (a + b)(a – b)


We get,


100 – (x – 5)2 = (10)2 – (x – 5)2


= {10 + (x – 5)}{10 – (x – 5)}


= (10 + x - 5)(10 – x + 5)


= (5 + x)(15 – x)


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