= 3,42 x 25,7 + 3,42 x 16,8 - 3,42 x 12 - 3,42 x 21,5 +3,42 x 1

=3,42 x ( 25,7 + 16,8 -12 - 21,5 + 1 )

=3,42 x 10

=34,2

34,2 nhé

câu thứ 1 là 17,5

a) 365.12.4+365.52=365.(12.4)+365.52=365.48+365.52=365.(48+52)=365.100=36 500

b)48.18+24.64=24.2.18+24.64=24.(2.18)+24.64=24.36+24.64=24.(36+64)=24.100=2 400

a)365x12x4+365x2

=365x48+365x2

=365(48+20

=365x50

=18250

b)48x18+24x64

=48x18+24x2x32

=48x18+48x32

=48x(18+32)

=48x50

=2400

\(\dfrac{12}{7}\) \(\times\) \(\dfrac{3}{4}\) - \(\dfrac{3}{4}\) \(\times\) \(\dfrac{12}{7}\)

= \(\dfrac{9}{7}\) - \(\dfrac{9}{7}\)

= 0 

a. c1:15x12-3x3x10 = 180-150=30

c2: 15x12-15x10 = 15x(12-10) = 15x2 = 30

b. c1: 45-9x18=45-162=-117

c2: 45-9x13-9x5=45-45-9x13=-117

c. c1: 29x6-19x16=174-304=-130

c2: 29x19-29x13-19x29+19x13=13x(19-29)=13x(-10)=-130

a. 

Cách 1: 

15.12 - 3.5.10

= 180 - 150

= 30

Cách 2:

15.12 - 3.5.10

= 15 .12 - 15.10

= 15. ( 12 -10)

= 15.2

= 30 

Tiếp tương tự. Chúc bạn học tốt!!

a) =180 - 15 x 10

    = 180 - 150 

    = 30

C2 ) 15 x 12 - 15 x 10

= 15 ( 12 - 10 ) 

=15 x 2

=30

b)= 45 - 162

=-117

C2) = 45 - (9 x 13 ) + ( 9 x 5 )

= 45 - 162

= -117

giup voi

15,42 x 139,2- 15,42 x 129,2 = 15,42 x (139,2 - 129,2 )

                                               = 15,42 x 100

                                               = 1542

15,42 x 139,2- 15,42 x 129,2

=15,42x(139,2-129,2)

=15,42x10

=154,2

7,8 x 0,35 x 2,1 + 0,35 x 0,1

=0,35 x (7,8+2,1+0,1)

=0,35 x 10

=3,5

\(\left(198,08\times23,56+165,9:27\right)\times\left(25,07\times3-75,21\right)+8,8\\ =\left(198,08\times23,56+165,9:27\right)\times\left(75,21-75,21\right)+8,8\\ =\left(198,08\times23,56+165,9:27\right)\times0+8,8\\ =0+8,8\\ =8,8\)

(198,08×23,56+ 165,9:27) × (25,07×3−75,21)+ 8,8

= (198,08 × 23,56 + 165,9 : 27) × (75,21 − 75,21) + 8,8

= (198,08× 23,56 +165,9:27) × 0 + 8,8

= 0+8,8

= 8,8

(198,08×23,56 + 165,9 : 27)×(25,07×3 − 75,21) + 8,8

= (198,08×23,56 + 165,9 : 27)×(75,21 − 75,21) + 8,8

= (198,08×23,56 + 165,9 : 27)×0 + 8,8

= 0 + 8,8

= 8,8