Hết cứu

Ta có: \(30\cdot4^7\cdot3^{29}-5\cdot14^5\cdot2^{12}\)

\(=2\cdot3\cdot5\cdot2^{14}\cdot3^{29}-5\cdot2^5\cdot7^5\cdot2^{12}\)

\(=2^{15}\cdot3^{30}\cdot5-2^{17}\cdot5\cdot7^5=2^{15}\cdot5\left(3^{30}-2^2\cdot7^5\right)\)

Ta có: \(54\cdot6^{14}\cdot9^7-12\cdot8^5\cdot7^5\)

\(=2\cdot3^3\cdot2^{14}\cdot3^{14}\cdot3^{14}-2^2\cdot3\cdot2^{15}\cdot7^5\)

\(=2^{15}\cdot3^{31}-2^{17}\cdot3\cdot7^5=2^{15}\cdot3\left(3^{30}-2^2\cdot7^5\right)\)

Ta có: \(A=\frac{30\cdot4^7\cdot3^{29}-5\cdot14^5\cdot2^{12}}{54\cdot6^{14}\cdot9^7-12\cdot8^5\cdot7^5}\)

\(=\frac{2^{15}\cdot5\left(3^{30}-2^2\cdot7^5\right)}{2^{15}\cdot3\cdot\left(3^{30}-2^2\cdot7^5\right)}=\frac53\)

1) \(7.4^x=7.4^3\Leftrightarrow4^x=4^3;x=3\)

2) \(\frac{3}{2.5^x}=\frac{3}{2.5^{12}}\Leftrightarrow5^x=5^{12};x=12\)

\(2^x=2.2^8=2^9;x=9\)

4) \(5.3^x=7.3^5-2.3^5\Leftrightarrow5.3^x=3^5.\left(7-2\right)\)

\(\Leftrightarrow3^5.x=3^5.5;x=5\)

0,5555897934

\(\frac{2^{12}\cdot5^7+4^6\cdot25^3}{8^5\cdot25^3+\left(2^2\cdot5\right)^6}\)

\(=\frac{2^{12}.5^7+2^{12}\cdot5^6}{2^{15}\cdot5^6+2^{12}\cdot5^6}\)

\(=\frac{2^{12}\cdot5^6\cdot\left(1\cdot5+1\right)}{2^{12}\cdot5^6\cdot\left(2^3\cdot1+1\right)}\)

\(=\frac{6}{9}\)

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

Bài này lớp 6 học rùi! 

S = 312/25

Bạn có cần giải cặn kẽ ko

A=\(\frac{16^3.3^{10}+120.6^9}{4^6.3^{12}+6^{11}}=\frac{\left(2^4\right)^3.3^{10}+2^3.3.5.2^9.3^9}{\left(2^2\right)^6.3^{12}+2^{11}.3^{11}}\)

\(=\frac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}+2^{11}.3^{11}}\)

\(=\frac{2^{12}.3^{10}.\left(1+5\right)}{2^{11}.3^{11}.\left(2.3+1\right)}\)

\(=\frac{2.6}{3.7}\)\(=\frac{4}{7}\)

dễ thế mà mày ko bít làm à

B=2(2/3.5 - 2/ 5.7 +....................+ 2/99.101) 

B=2(1/3.5 -2/5.7+..............+1/99.100)

B=2(1/3-1/5+1/5-.............+1/99-1/100)

B=2(1/3-1/100)

B=2.97/100

B=97/50