(x+0,2)+(x+0.7)+...+(x+4,7)=65,5

có số x là:(4,7-0,2):0,5+1=10(số)

=> x.10+(0,2+0,7+...+4,7)=65,5

=>x.10+24,5=65,5

=>x.10=65,5-24,5

=>x.10=41

=>x     =41:10

x=4,1

vậy x=1 tí nữa mik làm tiếp cho

(x+0,2)+(x+0.7)+...+(x+4,7)=65,5

có số x là:(4,7-0,2):0,5+1=10(số)

=> x.10+(0,2+0,7+...+4,7)=65,5

=>x.10+24,5=65,5

=>x.10=65,5-24,5

=>x.10=41

=>x     =41:10

x=4,1

vậy x=1

\(\left(\frac{1}{4}+35\%+0,65+75\%\right)x\)\(\left(1\frac{6}{3}+4\frac{8}{24}\right)\)

\(=\left(\frac{1}{4}+\frac{7}{20}+\frac{13}{20}+\frac{3}{4}\right)\)\(x\left(3+\frac{13}{3}\right)\)

\(=\left(\frac{5}{20}+\frac{7}{20}+\frac{13}{20}+\frac{15}{20}\right)\)\(x7\)

\(=2x7\)

\(=14\)

\(\left(\dfrac{1}{4}+35\%+0,65+75\%\right)\times\left(1\dfrac{6}{9}+4\dfrac{8}{24}\right)\)

\(=\left(0,25+0,35+0,65+0,75\right)\times\left(1+\dfrac{2}{3}+4+\dfrac{1}{3}\right)\)

\(=2\times6\)

\(=12\)

\(\left(\dfrac{1}{4}+35\%+0,65+75\%\right)\times\left(1\dfrac{6}{9}+4\dfrac{8}{24}\right)\)

\(=\left(\dfrac{1}{4}+\dfrac{7}{20}+\dfrac{65}{100}+\dfrac{3}{4}\right)\times\left(\dfrac{15}{9}+\dfrac{13}{3}\right)\)

\(=\left(\dfrac{5}{20}+\dfrac{7}{20}+\dfrac{13}{20}+\dfrac{15}{20}\right)\times6\)

\(=\left[\left(\dfrac{15}{20}+\dfrac{5}{20}\right)+\left(\dfrac{7}{20}+\dfrac{13}{20}\right)\right]\times6\)

\(=2\times6\)

\(=12\)

(75% + 0,65 + 1/4 + 35% ) x ( 5/4 + 125 x 3 + 12 x 0,625 )

=( \(\frac{3}{4}+0,65+\frac{1}{4}+3,5\) ) x ( \(\frac{5}{4}+125\)x 3 + 7,5 )

= ( 1 + 4,15 ) x ( \(\frac{5}{4}\) + 375 + 7,5 )

= 5,15 x 383,75

= 1976,3125

thank you dương tiến dũng  nhiều nha . hihihi

\(=\left(\frac{75}{100}+\frac{65}{100}+\frac{1}{4}+\frac{35}{100}\right)\left(\frac{1}{4}.2+\frac{25}{100}.3+\frac{25}{100}.5\right)\)

\(=\left(\frac{3}{4}+\frac{13}{20}+\frac{1}{4}+\frac{7}{20}\right)\left(\frac{2}{4}+\frac{3}{4}+\frac{5}{4}\right)\)

\(=\left(1+1\right).\frac{10}{4}\)

\(=2.\frac{5}{2}\)

\(=5\)

1).( 27,56 x 35 ) + ( 27,56 x 67 ) - ( 27,56 x 2)

= (964 + 1846,52) - 55,12

=2810,52 - 55,12

= 2755,4

2).( 4x 35 ) x ( 25 x 5 ) x 2

= ( 140 x 125 ) x2

= 17500 x 2

=35000

4). 3/10

5). 1188

6).  61/6

1)2756   2)35000   3)0   4)3/10   5)10/1/6

1,2755,4

2,35000

3,0

4,\(\frac{3}{10}\)

5,1188

6,\(\frac{61}{6}\)

= ( 25% + 35% + 65% + 75% ) x ( 1 + 2/3 + 4 + 1/3 )

= ( ( 25% + 75% ) + ( 35% + 65% ) ) x 6

= 2 x 6 = 12

\(\left(\frac{1}{4}+35\%+0,65+75\%\right)\)\(x\left(1\frac{6}{9}+4\frac{8}{24}\right)\)

\(=\left(\frac{1}{4}+\frac{7}{20}+\frac{65}{100}+\frac{3}{4}\right)\)\(x\left(\frac{15}{9}+\frac{13}{3}\right)\)

\(=\left(\frac{5}{20}+\frac{7}{20}+\frac{13}{20}+\frac{15}{20}\right)\)\(x6\)

\(=2x6\)

\(=12\)

= ( 25% + 35% + 65% + 75% ) x ( 1 + 2/3 + 4 + 1/3 )

= ( ( 25% + 75% ) + ( 35% + 65% ) ) x 6

= 2 x 6 

=12

   [\(\dfrac{1}{4}\) + 35% + 0,65% + 75% ]: [ 1\(\dfrac{6}{4}\) + 4\(\dfrac{8}{24}\)]

=  [25% + 35% + 0,65% + 75%] : [ \(\dfrac{10}{4}\) + \(\dfrac{104}{24}\)]

= [ (25% +75%) + (35% +0,65%)]:(\(\dfrac{60}{24}\) + \(\dfrac{104}{24}\))

= [ 100% + 35,65%]: \(\dfrac{41}{6}\)

= 135,65% : \(\dfrac{41}{6}\)

= \(\dfrac{13565}{10000}\) : \(\dfrac{41}{6}\)

= \(\dfrac{13565}{10000}\) \(\times\) \(\dfrac{6}{41}\)

= \(\dfrac{8139}{41000}\)