tìm phân số \(\frac{x}{y}\)biết \(x\cdot\frac{9}{11}=y\cdot\frac{6}{7}\)
tìm x,y,z
\(\frac{6}{11}\cdot x=\frac{9}{2}\cdot y=\frac{18}{5}\cdot z\)và \(-x+y+z=-120\)
Ta có: \(\frac{6x}{11}=\frac{9y}{2}=\frac{18z}{5}\Leftrightarrow\frac{-18x}{-33}=\frac{18y}{4}=\frac{18z}{5}\)
Áp dụng t/c của dãy tỉ số bằng nhau ta có:
\(\frac{-18x}{-33}=\frac{18y}{4}=\frac{18z}{5}=\frac{18\left(-x+y+z\right)}{-33+4+5}=\frac{18\cdot\left(-120\right)}{-24}=90\)
Do đó:
\(\frac{-18x}{-33}=90\Leftrightarrow x=165\)
\(\frac{18y}{4}=90\Leftrightarrow y=20\)
\(\frac{18z}{5}=90\Leftrightarrow z=25\)
Bài 1: Tìm x,y:
\(\frac{2\cdot x+1}{5}=\frac{3\cdot y-2}{7}=\frac{2\cdot x+3\cdot y-1}{6\cdot x}\)
tìm s biết \(\frac{1+2\cdot y}{18}=\frac{1+4\cdot y}{24}=\frac{1+6\cdot y}{6\cdot x}\)
Xin lỗi nha mk ms lp 6 ak nên ko hỉu.
Bn trả lời câu hỏi bên dưới của mk ik mk k cho!
Ta có : \(\frac{1+2y}{18}=\frac{1+4y}{24}\)
\(\Rightarrow24.\left(1+2y\right)=18.\left(1+4y\right)\)
\(\Rightarrow24+48y=18+72y\)
\(\Rightarrow24-18=72y-48y\)
\(\Rightarrow6=24y\Rightarrow y=\frac{6}{24}=\frac{1}{4}\)
Thay y vào đẳng thức ta có:
\(\frac{1+4.\frac{1}{4}}{24}=\frac{1+6.\frac{1}{4}}{6x}\)
\(\Rightarrow\frac{1}{12}=\frac{5}{2}:6x\)
\(\Rightarrow6x=\frac{5}{2}:\frac{1}{12}=30\)
\(\Rightarrow x=30:6=5\)
Ta có \(\frac{1+2y}{18}=\frac{1+6y}{6x}\)
áp dụng tính chất dãy tỉ số bằng nhau ta có
\(\frac{1+2y}{18}=\frac{1+6y}{6x}=\frac{1+2y+1+6y}{18+6x}=\frac{2+8y}{18+6x}=\frac{1+4y}{9+3x}\)
\(\Rightarrow\frac{1+4y}{24}=\frac{1+4y}{9+3x}\)
\(\Rightarrow\)\(9+3x=24\)
\(3x=24-9\)
\(3x=15\)
\(x=15\div3=5\)
Vậy x=5
Bai1:tìm x biết
a, (\(\frac{1}{7}\)\(\cdot\) x -\(\frac{2}{7}\))(-\(\frac{1}{5}x+\frac{3}{5}\))(\(\frac{1}{3}\cdot x+\frac{4}{3}\))
b, \(\frac{1}{6}\cdot x+\frac{1}{10}\cdot x-\frac{4}{5}\cdot x+1=0\)
c,(\(x-\frac{2}{9}\))^3=(\(\frac{2}{3}\))^6
d, (x-7)^x+1-(x-7)^x+11=0
Tìm x, y biết
\(25\%\cdot y+50\%\cdot y-\frac{3}{4}\cdot y+4\cdot y=10\)
\(x\cdot\frac{1}{4}-\frac{3}{4}=6:\frac{3}{4}\)
GIẢI NHANH GIÚP MÌNH VỚI
\(25\%.y+50\%.y-\frac{3}{4}.y+4.y=10\)
\(y.\left(\frac{1}{4}+\frac{1}{2}-\frac{3}{4}+4\right)=10\)
\(y.4=10\)
\(y=\frac{5}{2}\)
\(x.\frac{1}{4}-\frac{3}{4}=6:\frac{3}{4}\)
\(x.\frac{1}{4}-\frac{3}{4}=6.\frac{4}{3}\)
\(x.\frac{1}{4}=8+\frac{3}{4}\)
\(x.\frac{1}{4}=\frac{35}{4}\)
\(x=\frac{35}{4}:\frac{1}{4}\)
\(x=35\)
25% x y + 50% x y - 3/4 x y + 4 x y = 10
1/4 x y + 1/2 x y - 3/4 x y + 4 x y = 10
y x ( 1/4 + 1/2 - 3/4 + 4 ) = 10
y x 4 = 10
y = 10 : 4
y = 2.5
25%.y + 50%.y - \(\frac{3}{4}\).y + 4.y = 10
\(\frac{1}{4}\).y + \(\frac{1}{2}\).y - \(\frac{3}{4}\).y + 4.y = 10
y = 10 - 4 + \(\frac{3}{4}\) - \(\frac{1}{2}\)- \(\frac{1}{4}\)
y = 6
x. \(\frac{1}{4}\)- \(\frac{3}{4}\)= 6:\(\frac{3}{4}\)
x. \(\frac{1}{4}\)- \(\frac{3}{4}\)= 8
x. \(\frac{1}{4}\) = 8 + \(\frac{3}{4}\)
x. \(\frac{1}{4}\) = \(\frac{35}{4}\)
x = \(\frac{35}{4}\): \(\frac{1}{4}\)
x = 35
cho mik nha
\(7\cdot x-\frac{2}{3}\cdot y-2\cdot x+\frac{7}{9}\cdot y\)\(với\)\(x=\frac{-1}{10};y=4,8\)
\(7.\frac{-1}{10}-\frac{2}{3}.4,8-2.\frac{-1}{10}+\frac{7}{9}.4,8\)8
\(\frac{-7}{10}-\frac{16}{5}-\frac{1}{5}+\frac{56}{15}\)
\(=\frac{-11}{30}\)
tìm x biết
1, \(x-\frac{3}{5}=\frac{3}{35}-\frac{-7}{6}\)
2, \(\frac{x}{120}=\frac{3}{8}\cdot\frac{-4}{25}\)
3, \(\frac{11}{13}\cdot x=1\)
4, \(-\frac{9}{8}+\frac{-3}{8}\cdot x=\frac{-1}{8}\)
5, \(\frac{-2}{5}\cdot x+\frac{4}{3}=\frac{7}{3}\)
\(1,\)\(x-\frac{3}{5}=\frac{3}{35}-\frac{-7}{6}\)
\(x-\frac{3}{5}=\frac{3}{35}+\frac{7}{6}\)
\(x-\frac{3}{5}=\frac{263}{210}\)
\(x=\frac{263}{210}+\frac{3}{5}\)
\(x=\frac{389}{210}\)
VẬY: \(x=\frac{389}{210}\)
Tìm x : \(\frac{6:\frac{3}{5}-1\frac{1}{16}\cdot\frac{6}{7}}{4\frac{1}{5}\cdot\frac{10}{11}+5\frac{2}{11}}\)\(-\frac{\left(\frac{3}{20}+\frac{1}{2}-\frac{1}{5}\right)\cdot\frac{12}{49}}{3\frac{1}{3}+\frac{2}{9}}\)
1) Rút gọn phân số sau:
\(\frac{9^{14}\cdot25^5\cdot8^7}{18^{12}\cdot625^3\cdot24^3}\)
2) Tìm số tự nhiên n để phân số sau có giá trị là một số nguyên:
\(\frac{n+10}{2\cdot n-8}\)
3) Tìm số nguyên x,y biết
a)\(\frac{x}{y}=\frac{2}{7}\)
b) \(\frac{2\cdot x}{3}=\frac{x-2}{2}\)