\(\dfrac{34-x}{x+12}=\dfrac{8}{15}\\ \Rightarrow15.\left(34-x\right)=8.\left(x+12\right)\\ \Rightarrow510-15x=8x+96\\ \Rightarrow8x+15x=510-96\\ \Rightarrow23x=414\\ \Rightarrow x=18\)
Vậy \(x=18\)
Tìm x, biết:
\(\dfrac{x-9}{11}+\dfrac{x-10}{12}+\dfrac{x-11}{13}=\dfrac{x-12}{14}+\dfrac{x-28}{15}\)
Tìm x:
\(\dfrac{x+32}{11}+\dfrac{x+33}{12}=\dfrac{x+34}{13}+\dfrac{x+35}{14}\)
2. tìm x
a. \(\dfrac{2}{3}x+1=\dfrac{7}{15}\)
b. \(3^{x+2}-3^x=24\)
c. \(\dfrac{x}{12}=\dfrac{5}{9}\)
d. \(\dfrac{-2}{3}:x+\dfrac{5}{8}=\dfrac{-7}{12}\)
Tìm x ϵ N biết \(\dfrac{1}{4}.\dfrac{2}{6}.\dfrac{3}{8}.\dfrac{4}{10}......\dfrac{14}{30}.\dfrac{15}{32}=\dfrac{1}{2^x}\)
tìm x ∈ Z biết
\(\dfrac{1}{4}.\dfrac{2}{6}.\dfrac{3}{8}.\dfrac{4}{10}...\dfrac{15}{32}=2^x\)
Tìm số chưa biết
a)\(\dfrac{x}{y}=\dfrac{9}{7};\dfrac{y}{z}=\dfrac{7}{3};x=y-z=-15\)
b)\(\dfrac{x}{-3}=\dfrac{y}{-8};x^2-y^2=-\dfrac{44}{5}\)
2) Tìm x, y biết \(\dfrac{1+3y}{12}=\dfrac{1+5y}{5x}=\dfrac{1+7y}{4x}\)(với x, y khác 0)
Tìm x:
\(\dfrac{x-2}{11}+\dfrac{x-2}{12}+\dfrac{x-2}{13}=\dfrac{x-2}{14}+\dfrac{x-2}{15}\)
Tìm x:
\(\dfrac{x-2}{11}+\dfrac{x-2}{12}+\dfrac{x-2}{13}=\dfrac{x-2}{14}+\dfrac{x-2}{15}\)
