
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.





\(\frac{x}{27}\)= \(\frac{-2}{3,6}\)
\(\Leftrightarrow\)\(x\cdot3,6=27\cdot-2\)
\(\Leftrightarrow\)\(x\cdot3,6=-54\)
\(\Leftrightarrow\)\(x=-\frac{54}{3,6}\)
\(\Rightarrow\)\(x=-15\)

-564+[(-724)+564+224]
=(-564)+(-724)+564+224
=[(-564)+564]+[(-724)+224
= 0 + (-500) = -500

\(=>S=1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{49}-\dfrac{1}{50}\)
\(S=1-\dfrac{1}{50}=\dfrac{50}{50}-\dfrac{1}{50}=\dfrac{49}{50}\)
\(S=\dfrac{1}{1.2}+\dfrac{1}{2.3}+\dfrac{1}{3.4}+...+\dfrac{1}{49.50}\)
\(S=\dfrac{1}{1}-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{49}-\dfrac{1}{50}\)
\(S=\dfrac{1}{1}-\dfrac{1}{50}\)
\(S=\dfrac{50}{50}-\dfrac{1}{50}\)
\(S=\dfrac{49}{50}\)

C=-1,7.2,3+1,7.(-3,7)-1,7.3-1,7
C=1,7.(-2,3)+1,7.(-3,7)-1,7.3-1,7
C=1,7.(-2,3-3,7-3-1)
C=1,7,(-10)
C=-17


24 x 23 + 3 x 52
= 3 x 8 x 23 + 3 x 52
= 3 x 184 + 3 x 52
= 3 x ( 184 + 52 )
= 3 x 236
= 708
6) \(\dfrac{2}{7}+\dfrac{5}{7}\cdot\left(\dfrac{3}{5}-0,25\right)\cdot\left(-2\right)^2+35\%\)
\(=\dfrac{2}{7}+\dfrac{5}{7}\cdot\left(\dfrac{3}{5}-\dfrac{1}{4}\right)\cdot4+\dfrac{7}{20}\)
\(=1\cdot\dfrac{7}{20}\cdot4+\dfrac{7}{20}\)
\(=\left(1+4\right)\cdot\dfrac{7}{20}\)
\(=5\cdot\dfrac{7}{20}\)
\(=\dfrac{7}{4}\)