7.3^x=2^9+5.2^8
tính hợp lý 5. 2^29.3^18 -4.3^20 .2^27/5.2^9 .2^19.3^19-7.3^18.2^29
\(\dfrac{30.4^7.3^{29}-5.14^5.2^{12}}{54.6^{14}.9^2-12.8^5.7^5}\)
Mọi người giúp mình bài toán này
= \(\dfrac{5}{2}\)
bạn THAM KHẢO thôi nhé!
Kq = 5/2 nha bạn câu này đã có người hỏi rồi bạn tự tham khảo nhé
\(...=\dfrac{2.3.5.2^{14}.3^{29}-5.2^5.7^5.2^{12}}{3^2.2.3.2^{14}.3^{14}.3^4-3.2^2.2^{15}.7^5}\)
\(=\dfrac{2^{15}.3^{30}.5-2^{17}.5.7^5}{2^{15}.3^{21}-2^{17}.3.7^5}\)
\(=\dfrac{2^{15}.5\left(3^{30}-2^2.7^5\right)}{2^{15}.3.\left(3^{20}-2^2.7^5\right)}\)
\(=\dfrac{5\left(3^{30}-2^2.7^5\right)}{3.\left(3^{20}-2^2.7^5\right)}\)
a,-3/5.2/7+-3/7.3/5+-3/7
b,6^4.3^2.25^2-8^3.9^2.125/5^2.4^3.3^4
a,-3/5.2/7+-3/7.3/5+-3/7
=-3/7.2/5+(-3/7).3/5+(-3/7)
=-3/7(2/5+3/5+1)
=-3/7.2
=-6/7
\(\frac{-3}{5}\)và\(\frac{2}{7}\)mình đổi hai mẫu cho nhau
Tính giá trị biểu
B=\(\dfrac{30.4^7.3^{29}-5.14^5.2^{12}}{54.6^{14}.9^7-12.8^5.7^5}\)
Ta có: \(B=\dfrac{30\cdot4^7\cdot3^{29}-5\cdot14^5\cdot2^{12}}{54\cdot6^{14}\cdot9^7-12\cdot8^5\cdot7^5}\)
\(=\dfrac{3^{30}\cdot2^{15}\cdot5-5\cdot2^{17}\cdot7^5}{3^{31}\cdot2^{15}-2^{17}\cdot3\cdot7^5}\)
\(=\dfrac{2^{15}\cdot5\left(3^{30}-2^2\cdot7^5\right)}{3\cdot2^{15}\left(3^{30}-2^2\cdot7^5\right)}\)
\(=\dfrac{5}{3}\)
Tính :\(A=\frac{30.4^7.3^{29}-5.14^5.2^{12}}{54.6^{14}.9^7-12.8^5.7^5}\)
Câu 1: Rút gọn các biểu thức sau:
C = \(\dfrac{8^2.9^5}{3^9.4^3}\)
D = \(\dfrac{81^6.9^5}{27^7.3^{11}}\)
F = \(\dfrac{8^{15}.25^7}{125^5.2^{47}}\)
G = \(\dfrac{10^2.5^3}{8.25^2}\)
\(C=\dfrac{2^6\cdot3^{10}}{3^9\cdot2^6}=3\\ D=\dfrac{3^{24}\cdot3^{10}}{3^{21}\cdot3^{11}}=\dfrac{3^{34}}{3^{32}}=3^2=9\\ F=\dfrac{2^{45}\cdot5^{14}}{5^{15}\cdot2^{47}}=\dfrac{1}{2^2\cdot5}=\dfrac{1}{20}\\ G=\dfrac{2^2\cdot5^2\cdot5^3}{2^3\cdot5^4}=\dfrac{1\cdot5}{2}=\dfrac{5}{2}\)
C=3
D=9
F=1/20
G=5/2
Em ko giải chi tiết vì nó lâu
Mong thông cảm!
C= \(\dfrac{8^2.9^5}{3^9.4^3}\)
= \(\dfrac{\left(2^3\right)^2.\left(3^2\right)^5}{3^9.\left(2^2\right)^3}\)
= \(\dfrac{2^6.3^{10}}{3^9.2^6}\)
= \(\dfrac{3^1}{1}\)
= \(\dfrac{3}{1}\)
Tính
C = \(\frac{30.4^7.3^{29}-5.14^5.2^{12}}{5^4.6^{14}.9^7-12.8^5.7^5}\)
Tính
C= \(\frac{30.4^7.3^{29}-5.14^5.2^{12}}{54.6^{14}.9^7-12.8^5.7^5}\)
Mik ko chắc lắm đâu nha(/Mik làm tắc nên mất phấn tắc ra TSNT)
7.2^x=2^9+5.2^8
7.2ˣ = 2⁹ + 5.2⁸
7.2ˣ = 2⁸.(2 + 5)
7.2ˣ = 2⁸.7
2ˣ = 2⁸.7 : 7
2ˣ = 2⁸
x = 8