\(a)15.\left(\dfrac{212121}{434343}+\dfrac{333333}{353535}\right)\)

\(=15.\left(\dfrac{21}{43}+\dfrac{33}{35}\right)\)

\(=15.\dfrac{2154}{1505}\)

\(=\dfrac{6462}{301}\)

a)=15.2154/1505

=6462/301

b)=461179719/138076

c,=134724+400/135136-12

=135124/135124

=1

\(=15.\left(\frac{21.10101}{43.10101}+\frac{33.10101}{35.10101}\right)\)

\(=15.\left(\frac{21}{43}+\frac{33}{35}\right)\)

\(=15.\frac{2154}{1505}\)

\(=\frac{6462}{301}\)

1 a/ B = 2016 . 2016 - 2014 . 2018

           =\(2016^2-\left(2016-2\right).\left(2016+2\right)\)

           = \(2016^2-2016.\left(-2+2\right)\\\)

           =\(2016^2-2016.0 \)

           = \(2016^2\)

1: Tính
a) B = 2016 x 2016 - 2014 x 2018
       = (2016 x 2016) - (2014 x 2018)
       =  4064256 - 4064252
       = 4
       b) 327 x 412 + 400 / 328 x 412 -12
          = (327 x 412 + 400) / ( 328 x 412 - 12)
           = 135124 / 135124
           = 1

c) ( 1234 x 567 - 667 ) : ( 567 + 1234 x 5)
   = (1234 x 567 - 667) : (567 + 1234 x 566) 
= [1234 x 566 + (1234 - 667)] / (1234 x 566 + 567) 
= (1234 x 566 + 567) / (1234 x 566 + 567)
= 1
để thiếu bạn ơi
 

=15x(21/43+33/35)

=tự tính

nhưng tính nhanh mà cậu

327 x 412 + 400 =135124

328 x 412 - 12 = 135124

   327 x 412 + 400

= (328 - 1) x 412 + 400

= 328 x 412 - 412 + 400

=328 x 412 - 12

Vậy (327 x 412 + 400) / (328 x 412 - 12) = 1

Chúc em học tốt.

Cảm ơn các chị ak

15 x (\(\frac{212121}{434343}+\frac{333333}{3535335}\)) = 15 x ( \(\frac{21.10101}{43.10101}+\frac{33.10101}{35.10101}\))

= 15 x ( \(\frac{21}{43}+\frac{33}{35}\)) = 5 x 3 x \(\frac{735}{1505}+\frac{1419}{1505}\)= 5 x 3 x \(\frac{2154}{1505}\)= \(\frac{6462}{301}\)