Question

Tính hợp lí:

9) -48725 - ( 357 - 48725 ) + 300

10) 3579 - ( 49 - 5 + 3579 ) + 49

Answer 1

9) -48725 - ( 357 - 48725 ) + 300

= - 48725 + ( - 357) + 48725 + 300

= [ ( - 48725 ) + 48725 ] + [ ( - 357) + 300]

= 0 + ( -57)

= - 57

10) 3579 - ( 49 - 5 + 3579 ) + 49

= 3579 + ( -49) + 5 + ( -3579) +49

= [ 3579 + ( -3579) ] + [ ( - 49) + 49] + 5

= 0 + 0 + 5

= 5

Answer 2

9) - 48275 - ( 357 - 48725 ) + 300

= -48275 - 357 + 48725 +  300

= ( - 48725 + 48725 ) + ( -357 + 300)

= -57

10) 3579- ( 49 - 5 + 3579 ) + 49

= 3579 - 49 + 5 - 3579 + 49

= ( 3579 - 3579) + (-49 + 49) + 5

= 0+0+5= 5