25.34.4=25.4.34=100.34=3400

a) \(\dfrac{9}{25}=\dfrac{36}{100}=0,36\)

b) \(\dfrac{7}{4}=\dfrac{175}{100}=1,75\)

c) \(\dfrac{56}{200}=\dfrac{28}{100}=0,28\)

d) \(\dfrac{386}{300}=\dfrac{193}{150}\)

Bạn xem lại đề ý d!

386 – ( 287 + 386 ) – ( 13 + 0 ) 

= 386 – 287 – 386 – 13

= ( 386 – 386 ) – ( 287 + 13 )

= 0 – 300

= -300

\(386-\left(287+386\right)-\left(13+0\right)=386-287-386-13=-287-13=-300\)

bạn ơi ko dư

722 : 38 = 19 ( dư 0 )

10 2 + 7 2 2 + 7 . 5 1 + 7 = 5

386.62+386.a=38600

386.(62+a)=38600

62+a=100

a=38

     \(386\times62+386\times a\)\(=38600\)

\(\Leftrightarrow386\times\left(62+a\right)=38600\)

\(\Leftrightarrow62+a=38600:386\)

\(\Leftrightarrow62+a=100\)

\(\Rightarrow a=100-62\)

     \(a=38\)