\(\dfrac{72\times75}{125\times108}\) = \(\dfrac{36\times2\times25\times3}{25\times5\times36\times3}\) = \(\dfrac{2}{5}\)

12/7

\(\dfrac{12}{7}\)

\(\dfrac{72}{42}=\dfrac{72:6}{42:6}=\dfrac{12}{7}\)

12/7

12/7

12/7

\(\dfrac{-8}{12}=\dfrac{-8:4}{12:4}=\dfrac{-2}{3}\\ \dfrac{15}{-60}=\dfrac{15:15}{-60:15}=\dfrac{1}{-4}\\ \dfrac{-16}{-72}=\dfrac{-16:\left(-8\right)}{-72:\left(-8\right)}=\dfrac{2}{9}\\ \dfrac{35}{14.15}=\dfrac{5.7}{7.2.5.3}=\dfrac{1}{2.3}=\dfrac{1}{6}\)

-2/3

-1/4

2/9

1/6

-8/12= -2/3

15/-60= 1/-4

-16/-72= 2/9

35/14.15= 1/6

a: Các phân số tối giản là \(\dfrac{1}{3};\dfrac{4}{7};\dfrac{72}{73}\) vì ƯCLN(1;3)=1; ƯCLN(4;7)=1; ƯCLN(72;73)=1

b:

Các phân số rút gọn được là

 \(\dfrac{8}{12}=\dfrac{8:4}{12:4}=\dfrac{2}{3}\)

\(\dfrac{30}{36}=\dfrac{30:6}{36:6}=\dfrac{5}{6}\)

\(\dfrac{60}{72}=\dfrac{60:12}{72:12}=\dfrac{5}{6}\\ \dfrac{70}{95}=\dfrac{70:5}{95:5}=\dfrac{14}{19}\\ \dfrac{150}{360}=\dfrac{150:30}{360:30}=\dfrac{5}{12}\)

\(\dfrac{60}{72}=\dfrac{5}{6}\)

\(\dfrac{70}{95}=\dfrac{14}{19}\)

\(\dfrac{150}{360}=\dfrac{5}{12}\)

a. \(\dfrac{\sqrt{2}.\left(\sqrt{3}+\sqrt{5}\right)}{\sqrt{7}.\left(\sqrt{3}+\sqrt{5}\right)}=\dfrac{\sqrt{2}}{\sqrt{7}}=\sqrt{\dfrac{2}{7}}\)

d. \(\dfrac{\sqrt{6-2\sqrt{5}}}{\sqrt{5}-1}=\dfrac{\sqrt{5-2\sqrt{5}+1}}{\sqrt{5}-1}=\dfrac{\left(\sqrt{5}-1\right)^2}{\sqrt{5}-1}=\sqrt{5}-1\)

\(\sqrt{3-2\sqrt{2}}\)

a. Mẫu số chung nhỏ nhất là 24

b. \(\dfrac{5}{7}\)

c. \(\dfrac{3}{4}\)

d. \(\dfrac{9}{12}\) và giữ nguyên phân số còn lại

e. \(\dfrac{3}{6};\dfrac{4}{6};\dfrac{5}{6}\)

g. \(\dfrac{9}{12};\dfrac{4}{12};\dfrac{2}{12}\)

h. \(\dfrac{15}{60};\dfrac{20}{60};\dfrac{12}{60}\)

i. \(\dfrac{10}{1}\)

=6.23-6.6/6.22+6.12

=6.(23-6)/6.(22+12)

=6.17/6.34

=6.17/6.2.17

=1/2

=2.7.(- 2).(- 11).(- 2).(- 5).(- 2)/(- 11).2.2.(- 5).7.3

= 2.(- 2)/7.3

=- 4/21

\(\dfrac{6.23-36}{6.22+72}=\dfrac{6.23-6.6}{6.22+6.12}=\dfrac{6\left(23-6\right)}{6\left(22+12\right)}=\dfrac{1}{2}\)

\(\dfrac{2.\left(-14\right).22.10}{\left(-11\right).4.\left(-5\right).21}=\dfrac{1.\left(-14\right).2.2}{\left(-1\right).2.\left(-1\right).21}=-\dfrac{2}{21}\)