Tìm x biết
a, ( x + 1 ) + ( x + 4 ) + ( x + 7 ) + .... + ( x + 28 ) = 155
b, 1 + \(\frac{1}{3}\) + \(\frac{1}{6}\)+ \(\frac{1}{10}\) + ..... + \(\frac{2}{x.\left(x+1\right)}\)= \(1\frac{2009}{2010}\)
c, \(\left(\frac{2}{11.13}+\frac{2}{13.15}+\frac{2}{15.17}+....+\frac{2}{19.21}\right)\) . 462 - x = 19
a, (x+1)+(x+4)+(x+7)+...+(x+28)=155
=>x.10+(1+4+7+...+28) =155
=> x.10+145 =155
=> x.10 = 155-145
=> x.10 = 10
=> x =10:10
=> x =1
Vậy x= 1
x-\(\left(\frac{20}{11.13}+\frac{20}{13.15}+\frac{20}{15.17}+...+\frac{20}{53.55}\right)=\frac{3}{11}\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\)
\(\left(\frac{2}{11.13}+\frac{2}{13.15}+..............\frac{2}{19.21}\right).462-\frac{17}{x+1.05}=19\)
Tìm x
tìm X biết
\(\left(\frac{x}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right)-462-\left[0.04:\left(x+1,05\right)\right]:0,12=19\)
Tìm x, biết:
\(\left(\frac{2}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right).462-\left[2,04:\left(x+1,05\right)\right]:0,12=19\)
Tìm x biết:
\(\left(\frac{2}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right).462-\left[2,04:\left(x+1,05\right)\right]:0,12=19\)
Tìm x biết:
a,\(\frac{1}{2a^2+1}:x=2\)
b,\(x-\frac{20}{11.13}-\frac{20}{13.15}-\frac{20}{15.17}.........-\frac{20}{53.55}=\frac{3}{11}\)
c,\(\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+........+\frac{2}{x\left(x+1\right)}=\frac{2}{9}\)
tìm x biết
\(\left(\frac{x}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right)-462-\left[0,04:\left(x+1,05\right)\right]:0,12=19\)19
ai nhanh mik tick, help me
tìm x biết
\(\left(\frac{2}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right).462-\left[0,04:\left(x+1,05\right)\right]\)
Tìm x biết:
\(\left(\frac{2}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right).462-\left[2,04:\left(x+1,05\right)\right]:0,12=19\)
