Question

va rog
am nevoie de ajutor
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Answer 1

La ambele subpuncte se aplică formulele de calcul prescurtat:

(x+y)² = x² + 2·x·y + y²

(x-y)² = x² - 2·x·y + y²

a) ○ (a+1)² = a² + 2·a·1 + 1² = a² + 2a +1

○ (b+2)² = b² + 2·b·2 + 2² = b² + 4b + 4

○ (2c+3)² = (2c)² + 2·2c·3 + 3² = 4c² + 12c + 9

○ (√2 + 1)² = √2² + 2·√2 · 1 + 1² = 2 + 2√2 +1 = 3 + 2√2

○ (√3 + √2)² = √3² + 2·√3 · √2 + √2² = 3 + 2√6 + 2 = 5 + 2√6

b) ◎ (2a-1)² = (2a)² - 2·2a·1 + 1² = 4a² - 4a +1

◎ (3b-2)² = (3b)² - 2·3b·2 + 2² = 9b² - 12b + 4

◎ (c√2 - 3)² = (c√2)² - 2·c√2 · 3 + 3² = 2c² - 6c√2 + 9

◎ (√3 - 1)² = √3² - 2·√3 · 1 + 1² = 3 - 2√3 + 1 = 4 - 2√3

◎ (√5 - 2)² = √5² - 2·√5 · 2 + 2² = 5 - 4√5 + 4 = 9 - 4√5