Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1. Tìm x, biết:
a) \(\frac{4}{x}=\frac{8}{6}\). Ta có: \(\frac{8}{6}=\frac{8:2}{6:2}=\frac{4}{3}\Rightarrow x=3\)
b) \(\frac{3}{x-5}=\frac{4}{x+2}\). Ta có: \(5-2=3\)
\(\Rightarrow x=\left(3.5\right)+\left(4.2\right)+3=15+8+3=26\)
c) \(\frac{x}{-2}=\frac{-8}{x}\Rightarrow x=\left(-8\right):\left(-2\right)=4\)
2. Rút gọn
a) \(\frac{2^4.5^2.11^2.7}{2^3.5^3.7^2.11}\Leftrightarrow\frac{2^3.2^1.5^2.11.11.7}{2^3.5^2.5^1.7.7.11}\Leftrightarrow\frac{2^1.11}{5^1.7}=\frac{22}{35}\)
b) Tương tự
c) Tương tự
\(\frac{4}{x}=\frac{8}{6}\Rightarrow x=\frac{4.6}{8}=3\)
\(\frac{3}{x-5}=\frac{-4}{x+2}\Rightarrow3\left(x+2\right)=-4\left(x-5\right)\)
\(\Rightarrow3x+6=-4x+20\)
\(\Rightarrow3x+4x=20-6\)
\(\Rightarrow7x=14\)
\(\Rightarrow x=2\)
\(\frac{x}{-2}=\frac{-8}{x}\Rightarrow x^2=\left(-8\right)\left(-2\right)=16\Rightarrow x=\pm4\)
5+2.5+3.5+...+8.5+9.5
=5.(1+2+3+...+8+9)
=5.\(\frac{\left(9+1\right).9}{2}\)
=5.45
=225
a) 2^3.3^3.5^3.7.8/ 3.2^4.5^3.14= 2^6 . 3^3 . 5^3 . 7/ 3. 2^5. 7. 5^3
rút gọn sau đó ra kết quả: 2. 3^2=18
b) 9. 520. 279- 3.915.259/ 7.329. 1256- 3.39. 1519= 32. 520- 3.330.518/7.329.518- 310.319.519
=32. 520-331.518/ 7.329.518 - 329.519= 32. 518 ( 25-329) / 329. 518.2
tiếp theo em tu giai nhe
\(-\dfrac{5}{9}\times\dfrac{5}{11}+\dfrac{6}{9}\times\dfrac{5}{11}+\dfrac{5}{9}\)
\(=\dfrac{5}{11}\times\left(-\dfrac{5}{9}+\dfrac{6}{9}+\dfrac{5}{9}\right)\)
\(=\dfrac{5}{11}\times\dfrac{6}{9}\)
\(=\dfrac{30}{99}\)
\(=\dfrac{10}{33}\)
Cho mình sửa lại ạ:
\(-\dfrac{5}{9}\times\dfrac{5}{11}+\dfrac{6}{9}\times\dfrac{5}{11}+\dfrac{5}{9}\)
\(=\dfrac{5}{11}\times\left(-\dfrac{5}{9}+\dfrac{6}{9}\right)+\dfrac{5}{9}\)
\(=\dfrac{5}{11}\times\dfrac{1}{9}+\dfrac{5}{9}\)
\(=\dfrac{5}{99}+\dfrac{5}{9}\)
\(=\dfrac{60}{99}\)
\(=\dfrac{20}{33}\)
\(9.5^x=\left(6+3\right).5^6\)
\(9.5^x=9.5^6\)
\(5^x=5^6\)
\(x=6\)
9.5 mũ x = ( 6 + 3 ) . 5 mũ 6
9.5 mũ 5 = 9.5 mũ 6
5 mũ x = 5 mũ 6
x = 6