Question

> Dacă a + b = 1100 și b + 2c = 910, atunci a - 2c = ?
> Dacă a - b = 1000 şi c=100, atunci (a - b) xc = ?
Dacă 2a - 2b = 5500 şi 2c = 1000, atunci a - b - C = ?​

Answer 1

Răspuns:

$a+b = 1100\\\\b+2c=910\\\\scadem\: cele\:doua\:ecuatii\\\\a+b-b-2c=1100-910\Rightarrow \boxed{a-2c=190}$

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$a-b = 1000\\\\c=100\\\\(a-b)*c = 1000 * 100\\\\\boxed{(a-b)*c = 100 000}$

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$2a-2b = 5500\\\\2c = 1000\\\\2a-2b-2c = 5500 -1000\\\\2*(a-b-c) = 4500\\\\a-b-c=4500:2\\\\\boxed{a-b-c = 2250}$