2 ms·
You're not alone. (10a+b)(10c+d) = 100ac+10(ad+bc)+bd = 100ac+10(ac+ad+bc+bd-ac-bd)+bd = 100ac+10[(a+b)(c+d)-ac-bd]+bd. Quite pleasing, aesthetically.
by dhosek 5y ago
You're not alone. (10a+b)(10c+d) = 100ac+10(ad+bc)+bd = 100ac+10(ac+ad+bc+bd-ac-bd)+bd = 100ac+10[(a+b)(c+d)-ac-bd]+bd. Quite pleasing, aesthetically.