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Answer :
i)103 × 107 = (100 + 3)(100 + 7)
\([\because (x + a)(x + b) = x^2 + (a + b)x + ab]\)
We have,
\((100 + 3)(100 + 7) \)
\( = {100}^2 + (3 + 7)100 + (3)(7)\)
\(= 10000 + 1000 + 21\)
\(= 11021\)
ii)95 × 96 = (100 - 5)(100 - 4)
\([\because (x + a)(x + b) = x^2 + (a + b)x + ab] \)
We have,
\((100 - 5)(100 - 4) \)
\( = {100}^2 - (5 + 4)100 + (4)(5)\)
\(= 10000 - 900 + 20\)
\(= 9120\)
iii)104 × 96 = (100 + 4)(100 - 4)
\([\because (a^2 - b^2) = (a + b)(a - b)]\)
We have,
\((100 + 4)(100 - 4) \)
\( = {100}^2 - {4}^2\)
\(= 10000 - 16\)
\(= 9984\)