\(x+\dfrac{2}{3}=\dfrac{15}{6}\times\dfrac{9}{5}\)

\(x+\dfrac{2}{3}=\dfrac{5}{3}\times\dfrac{9}{5}\)

\(x+\dfrac{2}{3}=\dfrac{9}{3}\)

\(x=\dfrac{9}{3}-\dfrac{2}{3}\)

\(x=\dfrac{7}{3}\)

______________

\(\dfrac{15}{2}-x=\dfrac{7}{4}+\dfrac{5}{2}\)

\(\dfrac{15}{2}-x=\dfrac{7}{4}+\dfrac{10}{4}\)

\(\dfrac{15}{2}-x=\dfrac{17}{4}\)

\(x=\dfrac{15}{2}-\dfrac{17}{4}\)

\(x=\dfrac{30}{4}-\dfrac{17}{4}\)

\(x=\dfrac{13}{4}\)

x = 7/3

a) Số 5 nằm ở hàng trăm, và có giá trị là \(500\)

b) \(32567=30000+2000+500+60+7\)

a) Số 5 nằm ở hàng trăm, và có giá trị là 

500

500

b) 

32567

=

30000

+

2000

+

500

+

60

+

7

32567=30000+2000+500+60+7

Tổng chiều cao 8 bạn:

(5 + 2) x 145 + 129= 1144(cm)

Trung bình số đo chiều cao của 5 bạn nam và 3 bạn nữ là:

1144: (5+3)= 143(cm)

Đ.số: 143cm

5 x 5 

= 5 + 5 + 5 + 5 + 5

= 25 

5x5=25

8 1/3 - 5 1/2

= 25/3 - 11/2

= 83/6

8 1/3 - 5 1/2

= 25/3 - 11/2

= 83/6

 Học Tốt

=5,7 hay đọc là 57/10

3 1/2+2 1/5

=7/2+11/5

=35/10+22/10

=57/10

\(a,\dfrac{2727}{3131}=\dfrac{2727:101}{3131:101}=\dfrac{27}{31}\\ Vậy:\dfrac{27}{31}=\dfrac{2727}{3131}\)

\(a,2\dfrac{2}{3}+3\dfrac{3}{4}=\left(2+3\right)+\left(\dfrac{2}{3}+\dfrac{3}{4}\right)\\ =5+\dfrac{2\times4+3\times3}{12}\\ =5+\dfrac{17}{12}=5+1\dfrac{5}{12}=6\dfrac{5}{12}\\ b,2\dfrac{3}{5}\times7\dfrac{5}{6}=\dfrac{13}{5}\times\dfrac{47}{6}=\dfrac{611}{30}\)

\(c,1\dfrac{3}{5}-\dfrac{2}{3}+\dfrac{1}{3}=1\dfrac{3}{5}-\left(\dfrac{2}{3}-\dfrac{1}{3}\right)\\ =1\dfrac{3}{5}-\dfrac{1}{3}+\left(\dfrac{3}{5}-\dfrac{1}{3}\right)\\ =1+\dfrac{4}{15}=1\dfrac{4}{15}\)

\(d,4\dfrac{5}{6}:\dfrac{3}{4}\times2\dfrac{4}{5}=\dfrac{29}{6}\times\dfrac{4}{3}\times\dfrac{14}{5}\\ =\dfrac{29\times2\times2\times14}{2\times3\times3\times5}=\dfrac{29\times2\times14}{9\times5}=\dfrac{812}{45}\)

(285-y-0,15):0,25=60

284,85-y=60x0,25

284,85-y=15

y=284,85-15

y=269,85

nhớ tick cho mk nha