Question

Rezolva după modelul dat. ( 3+4+2) ×7=(3×7) +( 2×7)=...+ ....=. (3+6 +1) ×8= (2+3+5)×5= ( 1 +5+2)×6= (2+6+1)×9=

Answer 1

( 3 + 4 + 2 ) × 7 = 3 × 7 + 4 × 7 + 2 × 7 = 21 + 28 + 14 = 63 → aplic distributivitatea inmultirii fata de adunare → primul mod

( 3 + 4 + 2 ) × 7 = 9 × 7 = 63

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( 3 + 6 + 1 ) × 8 = 3 × 8 + 6 × 8 + 1 × 8 = 24 + 48 + 8 = 80 → primul mod

= 10 × 8 = 80 → al doilea mod

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( 2 + 3 + 5 ) × 5 = 2 × 5 + 3 × 5 + 5 × 5 = 10 + 15 + 25 = 50 → primul mod

= 10 × 5 = 50 → al doilea mod

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( 1 + 5 + 2 ) × 6 = 1 × 6 + 5 × 6 + 2 × 6 = 6 + 30 + 12 = 48 → primul mod

= 8 × 6 = 48 → al doilea mod

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( 2 + 6 + 1 ) × 9 = 2 × 9 + 6 × 9 + 1 × 9 = 18 + 54 + 9 = 81 → primul mod

= 9 × 9 = 81 → al doilea mod