Tính hợp lí

-48+48.(-78)+48.(-21) = 48.(-1) + 48.(-78) + 48.(-21) = 48. ( -1+ -78 + -21 ) = 48 .(-100) = -4800

=48.(-78-21)-48

=48.-100-48

=-4800-48

=-4848

-48 + 48 . (-78) + 48 . (-21)

= -48 . 1 + 48 .(-78) + 48 . (-21)

= 48 . (-1 - 78 - 21)

= 48 . (-100)

= -4800

k mik nha! thank you

-48 + 48 . (-78) + 48.(-21)

= 48 . (-1 - 78 - 21) 

= 48 . (-100)

= -4800

-48 + 48 . (-78) + 48 . (-21)

= -48 .1 + 48 . ( -78) + 48 . (-21)

= 48 . ( -1 - 78 - 21)

= 48 . (-100)

= -4800

45 - 5 . (12 + 9)

= 45 - 5 . 21

= 45 - 105

= -60

-48 + 48 . (-78) + 48 . (-21)

= -48 + (-48) . 78 + (-48) . 21

= -48 . (78 + 21 + 1)

= -48 . 100

= -4800

45 - 5 . (12 + 9)

= 45 - 5.21

=9 . 5 + 5 .21

= (9 + 21).5

= 30.5

= 150

-48 + 48 .(-78) + 48.(-21)

= 48.(-1 -78 - 21)

= 48.(-100) 

= -4800

k mik nha bn

45-5.(12+9)

=45-5.9+5.12

=45-45+60

=0+60=60

-48+48.(-78)+48.(-21)

= -48+(-48).78+(-48).21

= -48.(78+21+1)

= -48 . 100

= -4800

-48+48.(-78)+48.(-21)

= 48.[ (-1) +(-78) + (-21)] 

= 48.(-100)

= -4800

= (-48)+48.[(-78)+(-21)]

= (-48).1+ 48.(-99)

= 48.[(-99)+1]

= 48.(-100)

= -4800

-48+48.(-78)+48.(-21)

= -48+48.[(-78)+(-21)]

= 48.(-1)+48.(-99)

= 48.[(-1)+(-99)]

=48.(-100)

=-4800

-48 + 48. (-78) + 48.(-21)

=(-48).1+48.(-78) + 48.(-21)

=48.(-1)+48.(-78) + 48.(-21)

=48.[(-1)+(-78)+(-21)]

=48.(-100)

=(-4800)

\(\text{-48 + 48. (-78) + 48.(-21)}\)

\(=-48+\left(-48\right).78+\left(-48\right).21\)

\(=\left(-48\right).\left(1+78+21\right)\)

\(=\left(-48\right).100\)

\(=-4800\)

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-48+48.(-78)+48.(-21)

=48.(-1-78-21)

=48.-100

=-4800

happy new year

dễ mak bỏ ngoặc ra rùi tính thoy!!

-48+48.(-78)+48.(-21)

=-48.1+48.(-78)+48.(-21)

=48.[(-1)+(-78)+(-21)]

=48.(-100)

=-4800

K mk nha

-48+48.(-78)+48.(-21)

=48.(-1)+48.(-78)+48.(-21)

=48.(-1+(-78)+(-21))

=48.(-100)

=-4800

-48+48x(-78)+48x(-21)=-4800

-48 + 48 x ( -78 ) + 48 x ( -21 ) 

= -48 + 48 x [ (-78 ) + (-21 ) ]

= -48 + 48 x -99

= -48 + -4752

= -4800

(-48) + 48. (-78) + 48. (-21)

= (-48) + (-48). 78 + (-48). 21

= (-48). (1 + 78 + 21)

= (-48) . 100

= -4800

(-12). 47 + (-12). 52 + (-12)

= (-12). (47 + 52 + 1)

= (-12). 100

= -1200

\(\left(-48\right)+48.\left(-78\right)+48.\left(-21\right)\)

\(=48.\left(-1\right)+48.\left(-78\right)+48.\left(-21\right)\)

\(=48.\left(-1-78-21\right)\)

\(=48.\left(-100\right)\)

\(=-4800\)

(- 12). 47 + ( -12). 52 + ( -12)

\(=-12.\left(47+52+1\right)\)

\(=-12.100\)

\(-1200\)

(-48) + 48 . (-78) + 48 . (-21)

= (-48) + (-48) . 78 + (-48) . 21

= (-48) . (78 + 21 + 1)

= (-48) . 100

= -4800

(-12) . 47 + (-12) . 52 + (-12)

= (-12) . (47 + 52 + 1)

= (-12) . 100

= -1200