Question

Tính bằng cách thuân jtieenj nhất 

7/8 x 1/6 + 7/8 x 2/6 + 7/8x 1/2 

25 x 5 x 4 x 2 - 176

Answer 1

\(\dfrac{7}{8}\) \(\times\) \(\dfrac{1}{6}\) + \(\dfrac{7}{8}\) \(\times\) \(\dfrac{2}{6}\) + \(\dfrac{7}{8}\) \(\times\) \(\dfrac{1}{2}\)

= \(\dfrac{7}{8}\) \(\times\) ( \(\dfrac{1}{6}\) + \(\dfrac{2}{6}\) + \(\dfrac{1}{2}\) )

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

=  \(\dfrac{7}{8}\) \(\times\) ( \(\dfrac{1}{2}\) + \(\dfrac{1}{2}\))

= \(\dfrac{7}{8}\) \(\times\) 1

= \(\dfrac{7}{8}\)

    25 \(\times\) 5 \(\times\) 4 \(\times\)2  - 176

= (25 \(\times\) 4 ) \(\times\) ( 5 \(\times\) 2) - 176

= 100 \(\times\) 10 - 176

= 1000 - 176

= 824

Answer 2

\(\dfrac{7}{8}\times\dfrac{1}{6}+\dfrac{7}{8}\times\dfrac{2}{6}+\dfrac{7}{8}\times\dfrac{1}{2}\)

\(=\dfrac{7}{8}\times\left(\dfrac{1}{6}+\dfrac{2}{6}+\dfrac{1}{2}\right)\)

\(=\dfrac{7}{8}\times1\)

\(=\dfrac{7}{8}\)

__________________________ 

\(25\times5\times4\times2-176\)

\(=\left(25\times4\right)\times\left(4\times2\right)-176\)

\(=1000-176\)

\(=824\)

Chúc bạn học tốt

Answer 3

7/8x1/6+7/8x2/6+7/8x1/2

= 7/8x1/6+7/8x2/6+7/8x3/6

= 7/8x(1/6+2/6+3/6)

= 7/8x 1

= 7/8

25x5x4x2-176

=(25x4)x(5x2) -176

=100x10-176

=1000-176

=824

Answer 4

a, 7/8 x (1/6+2/6+1/2)

= 7/8 x 1

= 7/8

b, (25 x 4) x (5 x 2) -176

= 100 x 10 -176

=1000 - 176

= 824