Question

scrie numărul care lipsește 95×26=(95×20)+(95×?) 38×74=(38×?)+(38×?) 316×?=(316×20)+(316×7) ?×38=(457×30)+(?×?) 291×?=(?×60)+(?×1)

Answer 1

Răspuns

Explicație pas cu pas:

95 × 26 = ( 95 × 20 ) + (95 × ? )

95 × 26 = 95 × ( 20 + ? )  l : 95

26 = 20 + ?

26 - 20 = 6

Verific:    95 × 26 =( 95 × 20 ) +( 95 × 6 )

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38 × 74 = ( 38 × ? ) + ( 38 × ? )

38 × 74 = 38 × ( 70 + 4 ) = ( 38 × 70 ) + ( 38 × 4 )

→ descompun al doilea factor al produsului ca suma de zeci si unitati, apoi aplic distributivitatea inmultirii

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316 × ? = ( 316 × 20 ) + ( 316 × 7 )

( 316 × 20 ) + ( 316 × 7 ) = 316 × ( 20 + 7 ) = 316 × 27

→ am dat factor comun pe 316 din suma celor doua produse

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? × 38 = ( 457 × 30 ) + ( ? × ? )

457 × 38 = 457 × ( 30 + 8 ) = ( 457 × 30 ) + ( 457 × 8 )

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291 × ? + ( ? × 60 ) + ( ? × 1 )

291 × 61 =  291 × ( 60 + 1 ) = ( 291 × 60 ) + ( 291 × 1 )