Tìm số tự nhiên x biết:
\(\frac{6^{x+3}-6^{x+1}+6^x}{211}=\frac{7^{2x}+7^{2x+1}+7^{2x-3}}{8\frac{1}{49}}\)
Tìm x:
\(2x-3=x+\frac{1}{2}\)
\(4x-\left(2x+1\right)=3-\frac{1}{3}+x\)
\(2x-\frac{1}{2}-\frac{1}{6}-\frac{1}{12}-...-\frac{1}{49\cdot50}=7-\frac{1}{50}+x\)
1/ Rút gọn
\(A=\frac{4^5.9^4-2.6^9}{2^{10}.3^8-6^8.20}\)
\(B=\frac{2^{19}.27^3+15.4^9.9^4}{6^9.2^{10}+12^{10}}\)
2/ Tìm x
\(\frac{7^{x+2}+7^{x+1}+7^x}{57}=\frac{5^{2x}+5^{2x+1}+5^{2x+3}}{131}\)
Tìm x, biết
1) \(\frac{x-1}{x-5}=\frac{6}{7}\) 2) \(\frac{x-1}{3}=\frac{x+3}{5}\)
3) \(\frac{3}{7}=\frac{2x+1}{3x+5}\) 4) \(\frac{2x+3}{3x+1}=\frac{3}{4}\)
5) \(\frac{2x+3}{6}=\frac{7x-3}{15}\)
6) \(\frac{6x-5}{-7}=\frac{5x-3}{-5}\)
Câu 1: Tìm x
1/\(\frac{1+3x}{2}=\frac{7}{3}-\frac{x+1}{6}\)
2,\(\left|\frac{2x+1}{3}\right|=\left|\frac{x-1}{5}\right|\)
3,\(\left(\frac{4}{3}+2x\right)^3=\frac{8}{-27}\)
Tìm x biết:
a) \(\frac{x+1}{5}=\frac{x+2}{6}\)
b)\(\frac{x+1}{2}=\frac{8}{x+1}\)
c)\(\frac{2x-5}{5}=\frac{20}{2x-5}\)
d)\(\frac{37-x}{x+13}=\frac{3}{7}\)
1a)tìm x,y biết: \(4+\frac{x}{7+y}=\frac{4}{7}and:x+y=22\)
b)cho \(\frac{x}{3}=\frac{y}{4}\)và \(\frac{y}{5}=\frac{z}{6}\). Tính M=\(\frac{2x+3y+4z}{3x+4y+5z}\)
c) tìm x biết \(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}.\frac{4}{10}...\frac{30}{62}.\frac{31}{64}=2^x\)
d)\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2x\)
2. Tính:P=\(1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+...+\frac{1}{16}\left(1+2+..+16\right)\)
Tìm x biết
a) x+2x+3x+4x+...+100x=-213
b)\(\frac{1}{2}x-\frac{1}{3}=\frac{1}{4}x-\frac{1}{6}\)
c)3(x-2)+2(x-1)=10
d)\(\frac{x+1}{3}=\frac{x-2}{4}\)
e)\(\frac{x-6}{7}+\frac{x-7}{8}+\frac{x-8}{9}=\frac{x-9}{10}+\frac{x-10}{11}+\frac{x-11}{12}\)
f)\(\frac{x+32}{11}+\frac{x+23}{12}=\frac{x+38}{13}+\frac{x+27}{14}\)
Tìm x,y,z,biết:
1)2x=3y=4z và 2x-5z=-6
2)\(\frac{x+3}{5}=\frac{y-2}{3}=\frac{z-1}{7}\) và 3x+5y-7z=32
