đề sai

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

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

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

\(=\dfrac{3^{30}\cdot2^{15}\cdot5-5\cdot2^{17}\cdot7^5}{3^{31}\cdot2^{15}-2^{17}\cdot3\cdot7^5}\)

\(=\dfrac{2^{15}\cdot5\left(3^{30}-2^2\cdot7^5\right)}{3\cdot2^{15}\left(3^{30}-2^2\cdot7^5\right)}\)

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

= \(\dfrac{5}{2}\)

bạn THAM KHẢO thôi nhé!

Kq = 5/2 nha bạn câu này đã có người hỏi rồi bạn tự tham khảo nhé 

Mik ko chắc lắm đâu nha(/Mik làm tắc nên mất phấn tắc ra TSNT)

\(=\dfrac{3^{30}\cdot2^{15}\cdot5-5\cdot2^{17}\cdot7^5}{2^{14}\cdot3^{14}\cdot3^3\cdot2\cdot3^{14}-2^{15}\cdot7^5\cdot2^2\cdot3}\)

\(=\dfrac{2^{15}\cdot5\left(3^{30}-2^2\cdot7^5\right)}{2^{15}\cdot3^{31}-2^{17}\cdot7^5\cdot3}\)

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

B=5/3

B=\(\frac{5}{3}\)NHa bạn

ai cho mik ik