Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
!@#$%^&*(*&^%$#@!@#$%^&*(*&^%$#@!@#$%^&*(*&^%$#@!@#$%^&*(*&^%$#@!@#$%^&*(*&^%$#@!@#$%^&*(
Bài 3 :
b) Ta có 1+ 2 + 3 +4 + ...+ x =15
Nên \(\frac{x\left(x+1\right)}{2}=15\)
\(x\left(x+1\right)=30\)
=> \(x\left(x+1\right)=5.6\)
=> x = 5
Bài 2:
h; \(\dfrac{2}{3}\)\(x\) + 50% + \(x\) = \(\dfrac{1}{10}\)
\(\dfrac{2}{3}\)\(x\) + \(\dfrac{1}{2}\) + \(x\) = \(\dfrac{1}{10}\)
(\(\dfrac{2}{3}\)\(x\) + \(x\)) + \(\dfrac{1}{2}\) = \(\dfrac{1}{10}\)
\(x\) \(\times\) (\(\dfrac{2}{3}\) + 1) + \(\dfrac{1}{2}\) = \(\dfrac{1}{10}\)
\(x\) \(\times\) \(\dfrac{5}{3}\) + \(\dfrac{1}{2}\) = \(\dfrac{1}{10}\)
\(x\) \(\times\) \(\dfrac{5}{3}\) = \(\dfrac{1}{10}\) - \(\dfrac{1}{2}\)
\(x\) \(\times\) \(\dfrac{5}{3}\) = \(\dfrac{-2}{5}\)
\(x\) = \(\dfrac{-2}{5}\): \(\dfrac{5}{3}\)
\(x\) = - \(\dfrac{6}{25}\)
Lớp 5 chưa học số âm em nhé.
4/3 * [ 7/2 - 1 1/4 ] - 3/4 * x = 2
4/3 * [ 7/2 - 5/4 ] - 3/4 * x = 2
4/3 * [ 14/4 - 5/4] - 3/4 * x = 2
4/3 * 9/4 - 3/4 * x = 2
3 - 3/4 * x = 2
3/4 * x = 3 - 2
3/4 * x = 1
x = 1 : 3/4
x = 4/4 x 4/3 = 4/3
=> x = 4/3
5 * x - 4 * x = 24 * 5
5 * x - 4 * x = 120
x * ( 5 - 4 ) = 120
x * 1 = 120
x = 120 : 1
x = 120
Ủng hộ tui nha! ^^
bài2 \(x\times\dfrac{15}{16}-x\times\dfrac{4}{16}=2\)
\(x\times\dfrac{11}{16}=2\)
\(x=2:\dfrac{11}{16}\)
\(x=\dfrac{32}{11}\)
Bài 1 :
\(\dfrac{x}{16}\times\left(2017-1\right)=2\)
\(\dfrac{x}{16}\times2016=2\)
\(\dfrac{x}{16}=\dfrac{2}{2016}\)
\(x=\dfrac{2}{2016}\times16\)
\(x=\dfrac{1}{63}\)
Đặt \(A=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+...+\frac{1}{128}\)
\(2A=1+\frac{1}{2}+\frac{1}{4}+...+\frac{1}{64}\)
\(2A-A=\left(1+\frac{1}{2}+\frac{1}{4}+...+\frac{1}{64}\right)-\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+...+\frac{1}{128}\right)\)
\(A=1-\frac{1}{128}=\frac{127}{128}\)
Ủng hộ mk nha ^_-
\(2\cdot A=1+\frac{1}{2}+\frac{1}{4}+...+\frac{1}{64}\)
\(A=\left(1+\frac{1}{2}+\frac{1}{4}+...+\frac{1}{64}\right)-\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+...+\frac{1}{128}\right)\)
\(A=1-\frac{1}{128}=\frac{128}{128}-\frac{1}{128}=\frac{127}{128}\)
2.5 x \(\frac{25}{x}\)= \(\frac{5}{6}\)
\(\frac{62.5}{x}\)=\(\frac{5}{6}\)
\(x\)= 62.5 : \(\frac{5}{6}\)
\(x\)= 62.5 x \(\frac{6}{5}\)
\(x\)= 75
\(2.5\cdot\frac{25}{x}=\frac{5}{6}\)
\(=\frac{62.5}{x}=\frac{5}{6}\)
\(\Rightarrow62.5\cdot6=5x\)
375 = 5x
x = 375 : 5
x = 75