Question

efectuați utilizând factorul comun. dau coroana. cat mai repede.

Answer 1

a)   14 × 12 - 14 × 7 - 5 × 13 = 5

= 14 × ( 12 - 7 ) - 5 × 13 =

= 14 × 5 - 5 × 13 =

= 5 × ( 14 - 13 ) =

=  5 × 1 =

= 5

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b)   7 × 49 + 7 × 31 - 7 × 50 = 210

= 7 × ( 49 + 31 - 50 ) =

= 7 × 30 =

= 210

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c)  32 × 25 + 32 × 11 - 36 × 30 = 72

= 32 × ( 25 + 11 ) - 36 × 30 =

= 32 × 36 - 36 × 30 =

= 36 × ( 32 - 30 ) =

= 36 × 2 =

= 72

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d)   99 × 11 + 13 × 11 - 112 = 1 120

= 11 × ( 99 + 13 ) - 112 =

= 11 × 112 - 112 =

= 112 × ( 11 - 1 ) =

= 112 × 10 =

= 1 120

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e)    177 × 36 - 177 × 31 - 77 × 5 =

= 177 × ( 36 - 31 ) - 77 × 5 =

= 177 × 5 - 77 × 5 =

= 5 × ( 177 - 77 ) =

= 5 × 100 =

= 500

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f )   32 + 32 × 15 + 32 × 84 = 3 200

= 32 × ( 1 + 15 + 84 ) =

= 32 × 100 =

= 3 200