any of the tens i think (10=60, 20+50, etc.), but i am not too sure what is implied by regrouping. if i am right in thinking this only means "carrying" a digit after adding, then anything that adds up to 70 would work unless the sum of the digits in the ones place exceeded 9.
Two numbers that add up to 70 without regrouping can include pairs like 30 + 40, 25 + 45, or 20 + 50. Each of these pairs allows for simple addition that does not require carrying over. These pairs are easy to verify and understand in basic addition.
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Jawaban:Hasil dari [tex]\tt{} - 12 + ( - 15)[/tex] adalah [tex]\tt{} - 27.[/tex]Penjelasan dengan langkah-langkah:[tex]\tt{} - 12 + ( - 15)[/tex][tex]\tt{} = - (12 + 15)[/tex][tex]\tt{} = - 27 \\ \\ [/tex][tex] \huge \color{blue}\boxed{ \bf{} \star \: \: \color{green}BA\: \: \color{blue}\star \: }[/tex]