Question

tính thuận tiện

a, 46 * 42 + 46 * 5 + 23 * 2 * 10 + 46 * 42 + 46

b 5/3 * 1/9 + 5/3 * 5/9 + 5/3 * 7/9 - 5/3 * 4/9

 

Answer 1

a, 46*42+46*5+23*2*10+46*42+46=46*(42+5+10+42+1)=46*100=4600

b,5/3*1/9+5/3*5/9+5/3*7/9-5/3*4/9=5/3*(1/9+5/9+7/9-4/9)=5/3*1=5/3

Answer 2

a) 46 x 42 + 46 x 5 + 23 x 2 x 10 + 46 x 42 + 46

= 46 x 42 + 46 x 5 + 46 x 10 + 46 x 42 + 46

= 46 x (42 + 5 + 10 + 42 + 1)

= 46 x 100

= 4600

b) \(\frac{5}{3}\times\frac{1}{9}+\frac{5}{3}\times\frac{5}{9}+\frac{5}{3}\times\frac{7}{9}-\frac{5}{3}\times\frac{4}{9}\)

\(=\frac{5}{3}\times\left(\frac{1}{9}+\frac{5}{9}+\frac{7}{9}-\frac{4}{9}\right)\)

\(=\frac{5}{3}\times1\)

\(=\frac{5}{3}\)

Answer 3

\(a;46\times42+46\times5+23\times2\times10+46\times42+46\)

\(=46\times\left(42+5+10+42+1\right)\)

\(=46\times100=4600\)

Answer 4

\(b;\frac{5}{3}\times\frac{1}{9}+\frac{5}{3}\times\frac{5}{9}+\frac{5}{3}\times\frac{7}{9}-\frac{5}{3}\times\frac{4}{9}\)

\(=\frac{5}{3}\times\left(\frac{1}{9}+\frac{5}{9}+\frac{7}{9}-\frac{4}{9}\right)\)

\(=\frac{5}{3}\times\frac{9}{9}=\frac{5}{3}\)

Answer 5

a, 46 x 42 + 46 x 5 + 23 x 2 x 10 + 46 x 42 + 46

= 46 x 42 + 46 x 5 + 46 x 10 + 46 x 42 + 46 x 1

= 46 x ( 42 + 5 + 10 + 42 + 1 )

= 46 x 100

= 4600

b, 5/3 x 1/9 + 5/3 x 5/9 + 5/3 x 7/9 - 5/3 x 4/9

= 5/3 x ( 1/9 + 5/9 + 7/9 - 4/9 )

= 5/3 x 1

= 5/3