a: \(2\cdot25\cdot9\cdot4=25\cdot4\cdot9\cdot2=18\cdot100=1800\)

b: \(35\cdot112-12\cdot35+50\)

\(=35\left(112-12\right)+50\)

=3500+50

=3550

c: \(16+\left(5^{16}:5^{14}-9^0\right)\)

\(=16+5^2-1\)

=25+15

=40

d: \(24\cdot7-\left[181-\left(13-4\right)^2\right]\)

\(=168-181+9^2\)

=81-13

=68

a)2.25.9.4

=(25.4).(9.2)

=100.18

1800

b)35.112-12.35+50

=35.(112-12)+50

=35.100+50

=3500+50

=3550

c)\(16+\left(5^{16}:5^{14}-9^0\right)\)

\(=16+\left(5^2-9^0\right)\)

\(=16+\left(25-1\right)\)

\(=16+24\)

\(=40\)

d)\(24.7-[181-\left(13-4\right)^2]\)

\(=24.7-[181-9^2]\)

\(=24.7-[181-81]\)

\(=24.7-100\)

\(=168-100\)

\(=68\)

5²⁰ : ( 5¹⁵. 25 )

= 5²⁰ : ( 5¹⁵ . 5² )

= 5²⁰ : 5¹⁷ = 5³ = 125

\(=5^{20}:5^{17}=125\)

\(5^{20}:\left(5^{15}.15+5^{15}.10\right)\)

\(=5^{20}:5^{15}.\left(15+10\right)\)

\(=5^5.25\)

\(=5^7\)

\(=24\cdot16-24\cdot5-16\cdot24+16\cdot5=-8\cdot5=-40\)

\(1\frac{13}{15}.0,75-\left(\frac{104}{195}+25\%\right).\frac{24}{47}-3\frac{12}{13}:3\)

\(=\frac{28}{15}.\frac{3}{4}-\left(\frac{8}{15}+\frac{1}{4}\right).\frac{8}{9}-\frac{51}{13}.\frac{1}{3}\)

\(=\frac{7}{5}-\left(\frac{32}{60}+\frac{15}{60}\right).\frac{8}{9}-\frac{17}{13}\)

\(=\frac{7}{5}-\frac{47}{60}.\frac{8}{9}-\frac{17}{13}\)

\(=\frac{7}{5}-\frac{94}{135}-\frac{17}{13}\)

\(=\frac{-212}{351}\)

Tự quy đồng

\(2\frac{3}{4}.\left(-0,4\right)-1\frac{3}{5}.2,75+\left(-1,2\right):\frac{4}{11}\)

\(=\frac{11}{4}.\frac{-2}{5}-\frac{8}{5}.\frac{11}{4}-\frac{6}{5}.\frac{11}{4}\)

\(=\frac{11}{4}.\left(\frac{-2}{5}-\frac{8}{5}-\frac{6}{5}\right)\)

\(=\frac{11}{4}.\frac{-16}{5}\)

\(=\frac{-44}{5}=-8\frac{4}{5}\)

Ta có :\(274.24+76.312+24.226+188.76=24.\left(274+226\right)+76.\left(312+188\right)\)

\(=24.500+76.500\)

\(=500.\left(24+76\right)\)

\(=500.100\)

\(=50000\)

Bài này trong sách giáo khoa dễ mà bạn

=(274+226)x24+(188+312)x76

= 500        x24+  500       x76

= 500x(24+76)

= 500x100

=50 000

 274. 24 + 76. 312 + 24. 226 + 188. 76

= 24. ( 274 + 226 ) + 76. ( 312 + 188 )

= 24. 500 + 76. 500

= 500. ( 24 + 76 )

= 500. 100

=50000

-Học tốt ! -

a) 25.69+31.25-25.6

= 25.(69+31-6)

= 25.94

= 2350

b) 198:[130-(27-19)²]+2021⁰

= 198:[130-8²]+1

= 198:(130-64)+1

= 198:66+1

= 3+1

= 4

c) 5²⁰:[5¹⁵.(15+10)]

= 5²⁰:[5¹⁵.25]

= 5²⁰:(5¹⁵.5²⁾

= 5²⁰: 5¹⁷

= 5³

Ai tick mik mik tick lai cho

36+16+124+24

=(36+124)+(16+24)

=160+40

=200

200 vs lại olm - điểmNguyễn Hung Phat đê

Đặt A= -75.22,6+24.(-22,6)-22,6

Ta có A = -75.22,6+24.(-22,6)-22,6

              = 75. ( -22,6) + 24 . ( -22,6)-22,6

               = (-22,6 ) . ( 75 +24 -1)

                =-678

Công thức giải bài toán : a . (-b) =(-a ).b

a) (-124) + 24 = -100
b) 37. 78 + 37. 22
=  37 . ( 78 + 22 )
=  37 . 100
= 3700

\(a) (-124) + 24 = -100 b) 37. 78 + 37. 22 = 37 . ( 78 + 22 ) = 37 . 100 = 3700\)

a) (- 124) + 24                                          b) 37 . 78 + 37 . 22

= - ( 124 - 24)                                              =37 . ( 78 + 22)

= - 100                                                        =37 . 100 

                                                                    3700

12 x 78 - 24 x 19 

= 12 x 78 -  12 x 2 x 19

= 12 x 78 -  2 x 19 

= 12 x 78 -  (2 x 9)

= 12 x 78 -  38

= 12 x (78 - 38)

= 12 x 40 

= 480

12x78-24x19

=12x78-12x(2x19)

=12x78-12x38

=12x(78-38)

=12x40

=480

12 x 78 - 24 x 19

= 12 x 78 - ( 12 + 12 ) x 19

= 12 x 78 - 12 x 19 + 12 x 19

= 12 x ( 78 - 19 + 19 )

= 12 x 78

= 936