\(\dfrac{3^5}{5^5}.x=\dfrac{3^7}{7^7}\)
<=>\(x=\dfrac{3^7}{7^7}:\dfrac{3^5}{7^5}\)
<=>\(x=\dfrac{3^7.7^5}{7^7.3^5}\)
<=>\(x=\dfrac{3^2}{7^2}\)
<=>\(x=\dfrac{9}{49}\)
vậy x=\(\dfrac{9}{49}\)
Tính hợp lí: \(\left(\dfrac{3}{7}\right)^5\times\left(\dfrac{7}{3}\right)^{-1}\times\left(\dfrac{5}{3}\right)^6\div\left(\dfrac{343}{625}\right)^{-2}\)
\(\dfrac{5^5}{5^x}=5^{18}\)
\(\dfrac{x-7}{6}=\dfrac{3}{2\left(x-7\right)}\)
\(\left(\dfrac{-5}{8}\right)-x\div3\dfrac{5}{6}+7\dfrac{3}{4}=-2\)
1,Tìm x,biết
a,\(\left(-1\dfrac{3}{5}+x\right)\div\dfrac{12}{13}=2\dfrac{1}{6}\)
b,\(\dfrac{-4}{7}x+\dfrac{7}{5}=\dfrac{1}{8}\div\left(-1\dfrac{2}{3}\right)\)
bài 1 tính
a/ \(\left|1\dfrac{1}{2}-2\dfrac{1}{3}\right|^2+\left|1-\dfrac{5}{4}\right|\)
b/\(\left|\left(-1\right)^{100}-2\dfrac{1}{3}\right|+\dfrac{5}{6}\)
c/\(\left|\left(\dfrac{2}{3}\right)^{-1}-\dfrac{7}{4}\right|-\dfrac{7}{4}\)
d/ \(\left|x-5\right|+\left|x-8\right|\) với 5 \< x>/
Bài 17: Tìm x, biết
a) \(\left(\dfrac{1}{7}x-\dfrac{2}{7}\right)\left(-\dfrac{1}{5}x+\dfrac{3}{5}\right)\left(\dfrac{1}{3}x+\dfrac{4}{3}\right)=0\)
b) \(\dfrac{1}{6}x+\dfrac{1}{10}x-\dfrac{4}{15}x+1=0\)
Giúp mk vs, ai nhanh mk sẽ tick
Tìm x,y biết
a.\(\left(x-7\right)^{x+1}-\left(x-7\right)^{x+1}=0\)
b.\(\dfrac{5x-1}{3}=\dfrac{7y-6}{5}=\dfrac{5x+7y-7}{4x}\)
c.\(\left|x+5\right|+\left(3y-4\right)^{2017}=0\)
Tính:
a) S=1.2+2.3+3.4+...+99.100
b) B=\(\dfrac{49^{24}.125^{17}.2^8-5^{30}.7^{49}.4^5}{5^{29}.16^2.7^{48}}\)
c) C=\(\left(\dfrac{1}{3}+\dfrac{1}{3^2}+\dfrac{1}{3^3}+\dfrac{1}{3^4}\right).3^5+\left(\dfrac{1}{3^5}+\dfrac{1}{3^6}+\dfrac{1}{3^7}+\dfrac{1}{3^8}\right).3^9+...+\left(\dfrac{1}{3^{97}}+\dfrac{1}{3^{98}}+\dfrac{1}{3^{99}}+\dfrac{1}{3^{100}}\right).3^{101}\)
d) D= \(3-3^2+3^3-3^4+...+3^{2017}-3^{2018}\)
Tính hợp lí, tính nhanh( nếu có )
a)\(\dfrac{0,75-0,6+\dfrac{3}{7}+\dfrac{3}{13}}{2,75-2,2+\dfrac{11}{7}+\dfrac{11}{13}}\) c)\(-\left|1,5\right|.(1\dfrac{1}{3}-2)-\left|-\dfrac{2}{3}\right|\)
b)\(\dfrac{0,375-0,3+\dfrac{3}{11}+\dfrac{3}{12}\dfrac{ }{ }}{0.625-0,5+\dfrac{5}{11}+\dfrac{5}{12}}\) d)\([(\dfrac{2}{193}-\dfrac{3}{386}).\dfrac{193}{17}+\dfrac{33}{34}]:[(\dfrac{7}{2001}+\dfrac{11}{4002}.\dfrac{2001}{25}+\dfrac{9}{12}]\)