Zapisujemy według wzoru:

7, 8, 4, 6

$7\cdot 8-46=56-46=10$  

$7\cdot 8+46=56+46=102$  

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8, 9, 2, 5

$8\cdot 9-25=72-25=47$  

$8\cdot 9+25=72+25=97$  

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4, 9, 5, 8

$4\cdot 9+58=36+58=94$  

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6, 7, 2, 4

$6\cdot 7-24=42-24=18$  

$6\cdot 7+24=42+24=66$  

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6, 9, 1, 8

$6\cdot 9-18=54-18=36$  

$6\cdot 9+18=54+18=72$  

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9, 9, 6, 3

$9\cdot 9-63=81-63=18$  

$9\cdot 9+63=81+63=144$