(5c - 6) (5c + 6) - (5c - 6)² при c = 13

Question

(5c - 6) (5c + 6) - (5c - 6)² при c = 13

Answer 1

(5c - 6)(5c + 6) - (5c - 6)² = 25c² - 36 - (25c² - 60c + 36) =

= 25c² - 36 - 25c² + 60c - 36 = 60c - 72

если c = 13 , то :  60 * 13 - 72 = 780 - 72 = 708

Comments

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