II gimnazjum

Matematyka wokół nas 2

Pole rombu to połowa iloczynu długości jego przekątnych. P1​=21​cd

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−[−(−a−2b+3c)−(2a−3b−4c)−(3a+7b−5c)]=−[a+2b−3c−2a+3b+4c−3a−7b+5c]=−[−4a−2b+6c]=4a+2b−6c=2(2a+b−3c)=−2(−2a−b+3c)

Sprawdzamy każdą z 4 odpowiedzi: A.−(a−5)−(3a−4a)+6=−a+5−3a+4a+6=−a−3a+4a+5+6=11

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