a ) 

\(x+\frac{12}{15}=\frac{7}{5}\)

\(\Rightarrow x=\frac{7}{5}-\frac{12}{15}\)

\(\Rightarrow x=\frac{7}{5}-\frac{4}{5}\)

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

Vậy \(x=\frac{3}{5}\)

b ) 

\(x-\frac{6}{8}=\frac{3}{15}\)

\(\Rightarrow x-\frac{3}{4}=\frac{1}{5}\)

\(\Rightarrow x=\frac{1}{5}+\frac{3}{4}\)

\(\Rightarrow x=\frac{4}{20}+\frac{15}{20}\)

\(\Rightarrow x=\frac{19}{20}\)

Vậy \(x=\frac{19}{20}\)

~ Ủng hộ nhé 

\(x+\frac{12}{15}=\frac{7}{5}\)

\(\Rightarrow x=\frac{7}{5}-\frac{12}{15}\)

\(\Rightarrow x=\frac{7}{5}-\frac{4}{5}\)

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

1) Tính:

 1243 x 23 + 12 : 2 = 28589 + 6 =28595

 23 x 786 : 3 x 12 = 18078 : 3 x 12 = 6026 x 12 = 72312

2) Tính nhanh:

 12 x 4 + 23 x 2 x 2 = 12 x 4 + 23 x 4 = ( 12 + 23 ) x 4 = 35 x 4 = 140

 9 x 19 + 3 x 19 - 2 x 19 = ( 9 + 3 - 2 ) x 19 = 10 x 19 = 190

1) 28595

72312

2) 140

190

k mk nha, mk nhanh nhất đó

a,\(\frac{10x125x4x25x8}{0,8x0,04x1,25x25+0,6524+0,3476}\)

=\(\frac{10x\left(125x8\right)x\left(4x25\right)}{\left(0,8x1,25\right)x\left(0,04x25\right)+\left(0,6524+0,3476\right)}\)

=\(\frac{10x1000x100}{1x1+1}\)

=\(\frac{1000000}{2}\)=\(500000\)

b,\(\frac{3}{4}\)x X + 1,25 x X + 50% x X = 12,5 x 0,8

0,75 x X + 1,25 x X + 0,5 x X = 10

(0,75 + 1,25 + 0,5) x X = 10

2,5 x X = 10

       X = 10: 2,5 =4

=9

CHÚC BN HOK TỐT

TL

0

Xin k

HT

= 0
khỏi cần cảm ơn
 ~HT~

TL :

\(=0\)

HT

@@@@@@@@@@@@@@@@@@

   10 x 20 + 10 x 23 + 10 x 22 + 10 x 5 + 10 x 15 + 10 x 15 + 10 x 0

= 10 x (20 + 23 + 22 + 5 + 15 + 15) + 0

= 10 x 100

= 1000