Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a: \(\dfrac{33}{x}=\dfrac{y}{8}=\dfrac{z}{160}=\dfrac{45}{120}\)
=>33/x=y/8=z/160=3/8
=>x=88; y=33; z=60
b: \(\dfrac{x}{3}=\dfrac{14}{y}=\dfrac{z}{60}=\dfrac{-8}{12}=-\dfrac{2}{3}\)
nên x=-2; y=-21; z=-40
a) -12 => -11 => -10 => -9 => -8.
b) -1 => -11 => -5 => -3 => -1
..............................................................................................................................................................................................
a)Quy đồng: \(\frac{5}{8}=\frac{5.3}{8.3}=\frac{15}{24}\)
Vì \(\frac{5}{24}< \frac{10+5}{24}=\frac{15}{24}\)
\(\Rightarrow\frac{5}{24}< \frac{5+10}{24}=\frac{5}{8}\)
b) Quy đồng:
\(\frac{4}{9}=\frac{4.6}{9.6}=\frac{24}{9.6}\)
\(\frac{2}{3}=\frac{2.18}{3.18}=\frac{36}{9.6}\)
Vì \(\frac{36}{9.6}>\frac{24}{9.6}>\frac{6+9}{9.6}\)
\(\Rightarrow\frac{2}{3}>\frac{4}{9}>\frac{6+9}{6.9}\)
a) Chứng tỏ A không phải là số nguyên
Cho: \(A=1-\frac{3}{4}+\left(\frac{3}{4}\right)^2-\left(\frac{3}{4}\right)^3+\left(\frac{3}{4}\right)^4-.......-\left(\frac{3}{4}\right)^{2009}+\left(\frac{3}{4}\right)^{2010}\)
Đây là đề bài câu a nha các bn
Do bị lỗi nên đây là là câu a nha các bn
\(\dfrac{-5}{21}+\dfrac{-2}{21}+\dfrac{8}{24}=\dfrac{-7}{21}+\dfrac{8}{24}=\dfrac{-1}{3}+\dfrac{1}{3}=\dfrac{0}{3}=0\)\(\dfrac{-3}{7}+\dfrac{5}{13}+\dfrac{-4}{7}=(\dfrac{-3}{7}+\dfrac{-4}{7})+\dfrac{5}{13}=\dfrac{-7}{7}+\dfrac{5}{13}=\left(-1\right)+\dfrac{5}{13}=\dfrac{-13}{13}+\dfrac{5}{13}=\dfrac{-8}{13}\)
a) \(\dfrac{-3}{7}+\dfrac{5}{13}+\dfrac{-4}{7}=\left(\dfrac{-3}{7}+\dfrac{-4}{7}\right)+\dfrac{5}{13}\)
= -1+\(\dfrac{5}{13}\)
=\(\dfrac{-13}{13}+\dfrac{3}{13}\)
=\(\dfrac{-8}{13}\)
\(a.\left(\frac{1}{3}x\right):\frac{2}{3}=1\frac{3}{4}:\frac{2}{5}\)
\(\left(\frac{1}{3}x\right):\frac{2}{3}=\frac{35}{8}\)
\(\left(\frac{1}{3}x\right)=\frac{35}{8}:\frac{2}{3}\)
\(\left(\frac{1}{3}x\right)=\frac{35}{12}\)
\(x=\frac{35}{12}:\frac{1}{3}\)
\(x=\frac{35}{4}\)
\(b.4,5:0,3=2,25:\left(0,1.x\right)\)
\(\frac{9}{2}:\frac{3}{10}=\frac{9}{4}:\left(\frac{1}{10}x\right)\)
\(15=\frac{9}{4}:\left(\frac{1}{10}x\right)\)
\(\frac{1}{10}x=\frac{9}{4}:15\)
\(\frac{1}{10}x=\frac{3}{20}\)
\(x=\frac{3}{20}:\frac{1}{10}\)
\(x=\frac{3}{2}\)
\(c.8:\left(\frac{1}{4}x\right)=2:0,02\)
\(8:\left(\frac{1}{4}x\right)=2:\frac{2}{100}\)
\(8:\left(\frac{1}{4}x\right)=100\)
\(\frac{1}{4}x=8:100\)
\(\frac{1}{4}x=\frac{2}{25}\)
\(x=\frac{2}{25}:\frac{1}{4}\)
\(x=\frac{8}{25}\)
\(d.3:2\frac{1}{4}=\frac{3}{4}:\left(6.x\right)\)
\(\frac{27}{4}=\frac{3}{4}:\left(6.x\right)\)
\(6x=\frac{3}{4}:\frac{27}{4}\)
\(6x=\frac{1}{9}\)
\(x=\frac{1}{9}:6\)
\(x=\frac{1}{54}\)
a)
b) 4,5 : 0,3 = 2,25 : ( 0,1.x) => 0,1.x =
c)
d)
Chúc bạn học tốt!
A=3/2-5/6+/12-9/20+11/30-13/42+15/56-17/72+19/90
A=11/10
hok tốt nha