đáp án:251/30 

k cho mk nha

(7x6=5+2+6x7) =

\(\frac{5}{1.6}\)+ \(\frac{5}{6.11}\)+ .........+\(\frac{5}{501.506}\)

=\(\frac{1}{1.6}+\frac{1}{6.11}+.....+\frac{1}{501.506}\)

=\(\frac{1}{1}-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+......+\frac{1}{501}-\frac{1}{506}\)

=\(\frac{1}{1}-\frac{1}{506}\)

= tự tính nha

Giải

Làm thử thoi nhoa !

a)8,3.39-2,93.500+19,8.20

=323,7-1465+396

=323,7+396-1465

=719,7-1456

=-745,3

\(a,\frac{26}{60}+\frac{3}{15}=\frac{13}{30}+\frac{1}{5}=\frac{13}{30}+\frac{6}{30}=\frac{19}{30}\)

\(b,\frac{4}{26}+\frac{33}{78}=\frac{2}{13}+\frac{11}{26}=\frac{4}{26}+\frac{11}{26}=\frac{15}{26}\)

\(c,\frac{25}{40}-\frac{3}{12}=\frac{5}{8}-\frac{1}{4}=\frac{5}{8}-\frac{2}{8}=\frac{3}{8}\)

\(d,\frac{21}{27}+\frac{10}{54}+\frac{5}{15}=\frac{7}{9}+\frac{5}{27}+\frac{1}{3}=\frac{21}{27}+\frac{5}{27}+\frac{9}{27}=\frac{35}{27}\)

~Study well~

#Thạc_Trân

CẢM ƠN NHA

=(5/30+3/30+2/30) : (5/30+3/30-2/30)

=10/30 : 5/30

=10/30 x 30/5

=2

!!! Hok tốt!!!

\(\left(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right):\left(\frac{1}{6}+\frac{1}{10}-\frac{1}{15}\right)\)

=\(\frac{10}{30}:\frac{6}{30}\)

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

 minh lam hoi tat

\(\frac{2^{19}.\left(3^3\right)^3+3.5.\left(2^2\right)^9.\left(3^3\right)^4}{\left(2.3\right)^9.2^{10}+\left(8.9\right)^{10}}=\frac{2^{19}.3^9+5.2^{18}.3^9}{2^{19}.3^9+2^{30}.3^{20}}=\frac{2^{18}.3^9.\left(2+5\right)}{2^{18}.3^9.\left(2^{12}+3^{11}\right)}=\frac{7}{2^{12}+3^{11}}\)

tích mình với

ai tích mình

mình tích lại

thanks

35.(24−6.x)=0

24-6x= 0:35

24-6x=0

6x=24-0

6x=24

x=24:6=4

3.(x+7)−15=27

3(x+7)=27+15

3(x+7)=42

x+7=42:3

x+7=14

x=14-7=7

TK MIK NHA~~

\(\left(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right):\left(\frac{1}{6}+\frac{1}{10}-\frac{1}{15}\right)\)

=\(\frac{1}{3}+\frac{1}{5}\)

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

5/3 nhé bạn k nha