a) \(\frac{2}{5}+\frac{9}{15}=\frac{2}{5}+\frac{3}{5}=\frac{5}{5}=1\)

b) \(\frac{15}{45}+\frac{25}{30}=\frac{1}{3}+\frac{5}{6}=\frac{2}{6}+\frac{5}{6}=\frac{7}{6}\)

c) \(\frac{28}{32}+\frac{45}{72}=\frac{7}{8}+\frac{5}{8}=\frac{12}{8}=\frac{3}{2}\)

d) \(\frac{8}{28}+\frac{5}{30}=\frac{2}{7}+\frac{1}{6}=\frac{12}{42}+\frac{7}{42}=\frac{19}{42}\)

a) \(\frac{2}{5}+\frac{9}{15}\)=\(\frac{2}{5}+\frac{3}{5}=\frac{2+3}{5}=1\)

b)\(\frac{15}{45}+\frac{25}{30}=\frac{1}{3}+\frac{5}{6}=\frac{2}{6}+\frac{5}{6}=\frac{2+5}{6}=\frac{7}{6}\)

c)\(\frac{28}{32}+\frac{45}{72}=\frac{7}{8}+\frac{5}{8}=\frac{7+5}{8}=\frac{12}{8}=\frac{3}{2}\)

d)\(\frac{8}{28}+\frac{5}{30}=\frac{2}{7}+\frac{1}{6}=\frac{12}{42}+\frac{7}{42}=\frac{12+7}{42}=\frac{19}{42}\)

1.

a) \(\frac{16}{24}-\frac{1}{3}=\frac{16}{24}-\frac{8}{24}=\)\(\frac{8}{24}=\frac{1}{3}\)

b) \(\frac{4}{5}-\frac{12}{60}=\frac{48}{60}-\frac{12}{60}=\frac{36}{60}=\frac{9}{15}\)

3.

a)\(\frac{17}{6}-\frac{2}{6}=\frac{17-2}{6}=\frac{15}{6}\)

b) \(\frac{16}{15}-\frac{11}{15}=\frac{16-11}{15}=\frac{5}{15}=\frac{1}{3}\)

c) \(\frac{19}{12}-\frac{13}{12}=\frac{19-13}{12}=\frac{6}{12}=\frac{1}{2}\)

\(=\frac{2^{15}\cdot\left(3^2\right)^4}{2^7\cdot3^7\cdot\left(2^3\right)^3}\) 

\(=\frac{2^{15}\cdot3^8}{2^7\cdot3^7\cdot2^9}\) 

\(=\frac{2^{15}\cdot3^8}{2^{16}\cdot3^7}\) 

\(=\frac{3}{2}\)

Bài làm :

\(\frac{2^{15}.9^4}{6^7.8^3}\)

\(=\frac{2^{15}.\left(3^2\right)^4}{\left(2.3\right)^7.(2^3)^3}\)

\(=\frac{2^{15}.3^8}{2^7.3^7.2^9}\)

\(=\frac{3}{2}\)

Học tốt nhé

\(\frac{2^{15}.9^4}{6^7.8^3}=\frac{2^{15}.\left(3^2\right)^4}{2^7.3^7.\left(2^3\right)^3}=\frac{2^{15}.3^8}{2^7.3^7.2^9}=\frac{3}{2}\)

học tốt

            Bài làm :

Ta có :

\(\frac{2^{15}.9^4}{6^7.8^3}=\frac{2^{15}.\left(3^2\right)^4}{\left(2.3\right)^7.\left(2^3\right)^3}=\frac{2^{15}.3^8}{2^7.3^72^9}=\frac{3}{2}\)

Bài làm :

\(\frac{2^{15}.9^4}{6^7.8^3}\)

\(=\frac{2^{15}.\left(3^2\right)^4}{\left(2.3\right)^7.\left(2^3\right)^3}\)

\(=\frac{2^{15}.3^8}{2^7.3^7.2^9}\)

\(=\frac{3}{2}\)

Học tốt nhé

\(\frac{2^{15}.9^4}{6^7.8^3}\)\(=\frac{2^{15}.\left(3^2\right)^4}{\left(2.3\right)^7.\left(2^3\right)^3}\)\(=\frac{2^{15}.3^8}{2^7.3^7.2^9}\)\(=\frac{2^{15}.3^8}{2^{16}.3^7}\)\(=\frac{1.3^1}{2^1.1}\)\(=\frac{3}{2}\)

CHÚC BẠN HỌC TỐT

\(C=\frac{1}{x^2+6x+9}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}.\)

\(C=\frac{1}{\left(x+3\right)^2}+\frac{-1}{-\left(6x-x^2-9\right)}+\frac{x}{\left(x+3\right)\left(x-3\right)}\)

\(C=\frac{1}{\left(x+3\right)^2}+\frac{-1}{-6x+x^2+9}+\frac{x}{\left(x+3\right)\left(x-3\right)}\)

\(C=\frac{x-3}{\left(x+3\right)\left(x-3\right)}+\frac{-\left(x+3\right)}{\left(x+3\right)\left(x-3\right)}+\frac{x}{\left(x+3\right)\left(x-3\right)}\)

\(C=\frac{x-3.-x-3.x}{\left(x+3\right).\left(x-3\right)}=\frac{-6x}{\left(x+3\right)\left(x-3\right)}=\frac{-6x}{\left(x^2-9\right)}\)

2a) \(\frac{3^6+45^4-15^3.4^5}{27^4.25^3+45^6}\)

= \(\frac{3^6+\left(3^2.5\right)^4-\left(3.5\right)^3.\left(2^2\right)^5}{\left(3^3\right)^4.\left(5^2\right)^3+\left(3^2.5\right)^6}\)

= \(\frac{3^6+3^8.5^4-3^3.5^3.4^{10}}{3^{12}.5^6-3^{12}.5^6}=\frac{3^3.\left(3^3+3^5.5^4-5^3.4^{10}\right)}{0}\)(xem lại đề)

b)  \(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{16}{3}\right)^3:\left(\frac{4}{9}\right)^3}{2^7.5^2+512}\)

= \(\frac{\left(\frac{2}{5}.5\right)^7+\left(\frac{16}{3}:\frac{4}{9}\right)^3}{2^7.5^2+2^9}\)

= \(\frac{2^7+12^3}{2^7\left(5^2+2^2\right)}\)

= \(\frac{2^7+\left(2^2.3\right)^3}{2^7.29}\)

= \(\frac{2^7+2^6.3^3}{2^7.29}\)

= \(\frac{2^6\left(1+27\right)}{2^7.29}=\frac{28}{2.29}=\frac{14}{29}\)

mk xin lỗi bn nhé...mk vt nhầm đề...mk vt lại nha:

2a,\(\frac{3^6+45^4-15^3.9^5}{27^4.25^3+45^6}\)