Question

Вычислите:



100000001^2 – 99999999^2

Answer 1

100000001²-99999999²=400000000
$1) \: 10000001 \times 100000001 = \\ = 10000000200000001 \\ 2) \: 99999999 \times 99999999 = \\ = 9999999800000001 \\ 3) \: 10000000200000001 - \\ - 9999999800000001 = \\ = 400000000$
Или по формуле: (а+b)(a-b)=a^2-b^2.
(100000001+99999999)(100000001-99999999)=200000000*2=400000000