a) 14.95+10.25.7+20.70

=(14.5).(95:5)+(10.7).25+20.70

=70.19+70.25+20.70

=70.(19+25+20)

=70.64

=4480

b)(39.42-37.42):42

=42.(39-37):42

=42.2:42

=2.(42:42)

=2.1

=2

1) 20 - (x + 16) = 5

=> x + 16 = 20 - 5 = 15

=> x = 15 - 16 = -1

Vậy x = -1

2) 14.35.5+10.25.7+20.70

= (14.5).35 + (10.7).25 + 20.70

= 70.35 + 70.25 + 20.70

= 70.(35+25+20)

= 70.80

= 5600

3) 22344 + 44688.82

= 22344 + 22344.2.82

= 22344.(1+164)

= 22344.165

= 3686760

Đúng 100%

1) 20 - ( x + 16 ) = 5 

            x + 16 = 20 - 5 

            x + 16 = 15 

           x          = -1

tk mk nha ^_^

1) \(20-\left(x+16\right)=5\)

\(\Leftrightarrow x+16=20-5\)

\(\Leftrightarrow x+16=15\)

\(\Leftrightarrow x=15-16\)

\(\Leftrightarrow x=-1\)

vậy x=-1

2) a) \(14\cdot35\cdot5+10\cdot25\cdot7+20\cdot70\)

\(=\left(14\cdot5\right)\cdot35+\left(10\cdot7\right)\cdot25+20\cdot70\)

\(=70\cdot35+70\cdot25+70\cdot20\)

\(=70\left(35+25+20\right)\)

\(=70\cdot80\)

\(=5600\)

b) \(22344\cdot36+44688\cdot82\)

\(=\left(22344\cdot2\right)\cdot36:2+44688\cdot82\)

\(=44688\cdot18+44688\cdot82\)

\(=44688\left(18+82\right)\)

\(=44688\cdot100\)

\(=4468800\)

A=4480

B=2

C=30

a) \(\text{13 x 58 x 4 + 32 x 26 x 2 + 52 x 10 }\)

\(\text{=(13 x 4 ) x 58 + 32 x 13 x 2 x 2 + 13 x 4 x 10}\)

\(\text{= ( 13 x 4 ) x 58 + 32 x ( 13 x 2 x 2 ) + ( 13 x 4 ) x 10 }\)

\(\text{= 52 x 58 + 32 x 52 + 52 x 10}\)

\(\text{=52 x ( 58 + 32 + 10 )}\)

\(\text{=52 x 100 = 5200}\)

b) \(\text{14 x 35 x 5 + 10 x 25 x 7 + 20 x 70 x 2}\)

\(\text{= ( 14 x 5 ) x 35 + (10 x 7 ) x 25 + 20 x 70 x 2 }\)

\(\text{= 70 x 35 + 70 x 25 + 20 x 2 x 70 }\)

\(\text{= 70 x ( 35 + 25 + 40 )}\)

\(\text{= 70 x 100 = 7000 }\)

e) \(\text{5.3.37.4+5.24.21+21.5.12}\)

\(\text{= 5.(3.37.4+24.21+21.12)}\)

\(\text{= 5.1200}\)

\(=6000\)

a) \(13.58.4+32.26.2+52.10\)

\(=52.58+32.52+52.10\)

\(=52.\left(58+32+10\right)\)

\(=52.100=5200\)

b) \(14.35.5+10.25.7+20.70\)

\(=7.5.35.2+10.7.25+20.70\)

\(=35.70+70.25+20.70\)

\(=70\left(35+25+20\right)\)

\(=70.80=5600\)

c) \(...=15\left(27+18+6+23+12\right)\)

\(=15\left(27+23+18+12+6\right)\)

\(=15\left(50+30+6\right)=15.86=1290\)

d) \(...=53\left(51+4+49+96+1\right)\)

\(=53\left(51+49+4+96+1\right)\)

\(=53\left(100+100+1\right)=53.201=10653\)

e) \(15.37.4+120.21+21.5.12\)

\(=15.4.37+60.2.21+21.60\)

\(=60.37+60.42+21.60\)

\(=60.\left(37+42+21\right)=60.100=6000\)

13.58.4 + 32.26.2 + 52.10

= 52.58 + 32.52 + 52.10

= 52.(58+32+10)

= 52.100

=5200

b) 15.37.4 + 120.21 + 21.2.12

= 3.4.5.37 + 12.10.21 + 21.2.12

= 12.185 + 12.210 + 12.42

= 12 ( 185+210+42)

= 12.437

= 5244

c) 25.4 + 10.225 + 6.50

= 100 + 10.225 + 300

= 10.10+10.225+10.30

= 10(10+225+30)

= 10.265

= 2650

rùi giải tiếp

a) 29.64 - 29.24 + 40.81 = 

29.(64 - 24) + 40.81 =

29.40 + 40.81 = 

40.(29 + 81) =

40.110 = 4400

b) 14.35.5 + 10.25.7 + 20.70 =

70.35 + 70.25 + 20.70 = 

70.(35 + 25 + 20) = 

70.80 = 5600

c) 48.25 + 48.35 + 48.12 + 52.72 = 

48.(25 + 35 + 12) + 52.72 = 

48.72 + 52.72 = 

72. (48 + 52) = 

72.100 = 7200

d) 15.37.4 + 120.21 + 21.5.12 = 

60.37 + 60.2.21 + 21.60 =

60.(37 + 42 + 21) = 

60.100 = 6000

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