Question

subtract:
$5a {}^{2} - 3ab + b {}^{2} from7a {}^{2} - 2ab - 4b {}^{2}$
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Answer 1

$5a²-3ab+b² from 7a²-2ab -4b² \\ 7a²-2ab -4b² - 5a²-3ab+b² \\ 7a²+5a²-2ab+3ab-4b²-b² \\12a²-5ab-3b²$