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Question

tính nhanh

a, 53.39+47.39-53.21-47.21

b,2.53.12+4.6.87-3.8.40

c, 5.7.77-7.60+49.25-15.42

Tài Nguyễn Tuấn · Accepted Answer

a) $53.39+47.39-53.21-47.21$

$=39.(53+47)-21.(53+47)$

$=(39-21).100=18.100=1800$

b) $2.53.12+4.6.87-3.8.40$

$=24.53+24.87-24.40=24.(53+87-40)=24.100=2400$

c) $5.7.77-7.60+49.25-15.42$

$=7.385-7.60+7.175-90.7$

$=7.(385-60+175-90)=7.410=2870$Câu trả lời: a) $53.39+47.39-53.21-47.21$

$=39.(53+47)-21.(53+47)$

$=(39-21).100=18.100=1800$

b) $2.53.12+4.6.87-3.8.40$

$=24.53+24.87-24.40=24.(53+87-40)=24.100=2400$

c) $5.7.77-7.60+49.25-15.42$

$=7.385-7.60+7.175-90.7$

$=7.(385-60+175-90)=7.410=2870$

Mashiro Shiina · Answer

$53.39+47.39-53.21-47.21$

$=39(47+53)-21(47+53)$

$=(39-21)(47+53)$

$=18.100=1800$

$2.53.12+4.6.87-3.8.40$

$=24.53+24.87-24.40$

$=24(53+87-40)=24.100=2400$

$5.7.77-7.60+49.25-15.42$

$=385.7-7.60+7.7.25-15.6.7$

$=385.7-7.60+7.175-7.90$

$=7(385-60+175-90)=7.410=2870$Câu trả lời: $53.39+47.39-53.21-47.21$

$=39(47+53)-21(47+53)$

$=(39-21)(47+53)$

$=18.100=1800$

$2.53.12+4.6.87-3.8.40$

$=24.53+24.87-24.40$

$=24(53+87-40)=24.100=2400$

$5.7.77-7.60+49.25-15.42$

$=385.7-7.60+7.7.25-15.6.7$

$=385.7-7.60+7.175-7.90$

$=7(385-60+175-90)=7.410=2870$

Kirigaya Kazuto · Answer

a, 53.39+47.39-53.21-47.21

=39.(53+47)-21.(53+47)

=39.100-21.100

=100.(39-21)

=100.18

=1800

b,b,2.53.12+4.6.87-3.8.40

=24.53+24.87-24.40

=24.(53+87-40)

=24.100

=2400

c,5.7.77-7.60+49.25-15.42

=7.385-7.60+7.175-90.7

=7.(385-60+175-90)

=7.410

=2870

Chúc bạn học tốtCâu trả lời: a, 53.39+47.39-53.21-47.21