1a)  x + 2/5 = 1/2 =5/10-4/10=1/10

b=2/7+2/5=10/35+14/35=24/35

a/\(x-\dfrac{5}{7}-\dfrac{13}{14}=1\)
\(x=1+\dfrac{5}{7}+\dfrac{13}{14}\)
\(x=\dfrac{14}{14}+\dfrac{10}{14}+\dfrac{13}{14}\)
\(x=\dfrac{37}{14}\)
Vậy \(x=\dfrac{37}{14}\)
b/\(\dfrac{3}{5}+x+1\dfrac{1}{5}=\dfrac{11}{3}\)
\(x+\dfrac{3}{5}+\dfrac{6}{5}=\dfrac{11}{3}\)
\(x+\dfrac{9}{5}=\dfrac{11}{3}\)
\(x=\dfrac{11}{3}-\dfrac{9}{5}\)
\(x=\dfrac{55}{15}-\dfrac{27}{15}\)
\(x=\dfrac{28}{15}\)
Vậy \(x=\dfrac{28}{15}\)
#kễnh

a) \(x-\dfrac{5}{7}-\dfrac{13}{14}=1\)

\(x-\dfrac{23}{14}=1\)

\(x=1+\dfrac{23}{14}\)

\(x=\dfrac{37}{14}\)

b) \(\dfrac{3}{5}+x+1\dfrac{1}{5}=\dfrac{11}{3}\)

\(x+1+\dfrac{3}{5}+\dfrac{1}{5}=\dfrac{11}{3}\)

\(x+\dfrac{9}{5}=\dfrac{11}{3}\)

\(x=\dfrac{11}{3}-\dfrac{9}{5}\)

\(x=\dfrac{28}{15}\)

lồn chó sủa

Gyug : Hãm loz bn êy

\(\left(6:3,5-1\dfrac{1}{6}\times\dfrac{6}{7}\right):\left(4,2\times\dfrac{10}{11}+5\dfrac{2}{11}\right)\\ =\left(\dfrac{12}{7}-\dfrac{7}{6}\times\dfrac{6}{7}\right):\left(\dfrac{21}{5}\times\dfrac{10}{11}+\dfrac{57}{11}\right)\\ =\left(\dfrac{17}{7}-1\right):\left(\dfrac{42}{11}+\dfrac{57}{11}\right)\\ =\dfrac{10}{7}:9\\ =\dfrac{10}{63}\)

\(\left(6:\dfrac{3}{5}-1\dfrac{1}{6}\times\dfrac{6}{7}\right):\left(4,2\times\dfrac{10}{11}+5\dfrac{2}{11}\right)\)

\(=\left(6\times\dfrac{5}{3}-\dfrac{7}{6}\times\dfrac{6}{7}\right):\left(\dfrac{21}{5}\times\dfrac{10}{11}+\dfrac{57}{11}\right)\)

\(=\left(10-1\right):\left(\dfrac{42}{11}+\dfrac{57}{11}\right)=9:9=1\)

c)\(\dfrac{3}{8}\times\dfrac{5}{8}+y=\dfrac{5}{4}\) 

   \(\dfrac{15}{64}+y=\dfrac{5}{4}\) 

           \(y=\dfrac{5}{4}-\dfrac{15}{64}\) 

           \(y=\dfrac{65}{64}\)

d, \(\dfrac{3}{8}+\dfrac{5}{8}\times y=\dfrac{5}{4}\) 

          \(\dfrac{5}{8}\times y=\dfrac{5}{4}-\dfrac{3}{8}\) 

          \(\dfrac{5}{8}\times y=\dfrac{7}{8}\) 

                 \(y=\dfrac{7}{8}:\dfrac{5}{8}\) 

                \(y=\dfrac{7}{5}\)

 a, 3/4 x y = 3/5 + 3/10   

3/4 x y = 9/10

y = 9/10 : 3/4

y = 6/5

b, 3/5 : y = 3/4 - 2/5

3/5 : y = 7/20

y = 3/5 : 7/20 

y = 12/7

các bn nào đang online giải hộ mk vs

a)\(\frac{21}{11}.\frac{22}{17}.\frac{68}{63}=\frac{21.22.68}{11.17.63}=\frac{21.2.11.4.17}{11.17.3.21}=\frac{\left(11.17.21\right)2.4}{\left(11.17.21\right).3}=\frac{2.4}{3}=\frac{8}{3}\)

b)\(\frac{5}{14}.\frac{7}{13}.\frac{26}{25}=\frac{5.7.26}{14.13.25}=\frac{5.7.13.2}{7.2.13.5.5}=\frac{\left(5.7.13\right).2}{\left(5.7.13\right).2.5}=\frac{2}{2.5}=\frac{1}{5}\)

a, 1+3+5+7+...+99

Khoảng cách 2 số hạng liên tiếp:

7-5=2(đơn vị)

Số lượng số hạng;

(99-1):2 + 1= 50(số hạng)

Tổng bằng:

(1+99) : 2 x 50 = 2500

Đ.số: 2500

c, 24 - 22 + 20 - 18 + 16 - 14 + 12 - 10 + 8 - 6

=(24-22) + (20-18) + (16-14) + (12-10) + (8-6)

= 2+2+2+2+2

=10

b,  1+4+7+...+28

Hiệu 2 số hàng kề nhau:

7-4=3(đơn vị)

Số lượng số hạng:

(28-1):3 +1= 10(số hạng)

Tổng bằng:

(28+1) : 2 x 10= 145

\(3ha7dam^2=307dam^2\)

3 ha 7 dam² = 307 dam²