Có:  \(35x+15=890\Rightarrow35x=875\Rightarrow x=25\)

\(1152-96\cdot y=\left(96\cdot y-96\cdot y\right)\cdot96\cdot y\)(dấu nhân viết là ".")

\(1152-96\cdot y=1\cdot96\cdot y\)

\(1152=96\cdot y+96\cdot y\)

\(1152=192\cdot y\)

\(y=\frac{1152}{192}\)

\(y=6\)

tinh bang cach thuan tien nhat

113 x 3 x 18 = 6102

= 6x3x113^3

= 18x113^3

= 25972146

\(=\dfrac{1}{2}\cdot\dfrac{2}{3}\cdot...\cdot\dfrac{7}{8}=\dfrac{1}{8}\)

`= 1/2 xx 2/3 xx...xx 7/8`

`= 1/8`

\(=\dfrac{1}{2}\times\dfrac{2}{3}\times\dfrac{3}{4}\times...\times\dfrac{6}{7}\times\dfrac{7}{8}\\ =\dfrac{1}{8}\)

\(B=\left(1-\dfrac{1}{3}\right)\cdot\left(1-\dfrac{1}{6}\right)\cdot\left(1-\dfrac{1}{10}\right)\cdot\left(1-\dfrac{1}{15}\right)\cdot...\cdot\left(1-\dfrac{1}{780}\right)\)

\(B=\left(1-\dfrac{1}{3+6+10+15+...+780}\right)\)

\(B=\left(1-\dfrac{1}{\left(780-3\right)\div3+1}\right)\)

\(B=\left(1-\dfrac{1}{260}\right)\)

\(B=\dfrac{259}{260}\)

 A) 325 + 612 + 675 + 388

= ( 325 + 612 ) + ( 675 + 388 )

=  937 + 1063

= 2000

 B) 268 x 8 + 315 x 33 + 315

= ( 268 x 8 ) + ( 315 x 33 ) + 315

= 2144 + 10395 + 315

= 12539 + 315

= 12854

 C) 315 x 66 + 315 x 33 + 325

= ( 315 x 66 ) + ( 315 x 33 ) + 325

= 20790 + 10395 + 325

= 31185 + 325

= 31510

 D) 2017 x 19 - 2017 x 8 - 2017

= ( 2017 x 19 ) - ( 2017 x 8 ) - 2017

=38323 - 16136 -2017

= 22187 - 2017

= 20170

 E) 3150 - 267 - 315 - 733 - 685

= ( 3150 - 267 ) - 315 - ( 733 - 685 )

= 2883 - 315 - 48

= 2568 - 48

= 2520

cho đề rõ hơn đi e