\(R=\left(1+2+3+...+90\right).\left(12,34-6,68\right):\left(\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{1}{6}\right)\)

\(R=4095.5,66:\frac{19}{20}\)

\(R=4095.5,66.\frac{20}{19}\)

\(R=24397,57895\)

Tính nhanh bạn ơi

Bạn tính nhanh thì mk k cho

[(1+90)x90:2]x5,66:19/20=4095x5,66:19/20=23177,7:19/20=

ta có 5^x+5^x*25=650 suy ra 5^x *26=650 ,5^x=25 suy ra x=2

Mk giúp phần đầu nhé!

Có 5^x+5^x+2=650

=> 5^x.(1+5²)=650

     5^x. 26=650

     5^x=650:26

     5^x=25

=> x=2

12*34=1*68

=>12*34-6*68=0=>bieu thuc = 0

a) \(\text{​​}/3x-5/-\frac{1}{7}=\frac{1}{3}\)                           b)\(\left(\frac{3}{5}x-\frac{2}{3}x-x\right).\frac{1}{7}=\frac{-5}{21}\)

  \(/3x-5/=\frac{10}{21}\)                                           \([x.\left(\frac{3}{5}-\frac{2}{3}-1\right)]=\frac{-5}{21}.7\)

 \(\Rightarrow3x-5=\frac{10}{21}hay3x-5=\frac{-10}{21}\)         \(\left[x.\frac{-16}{15}\right]=\frac{-5}{3}\)

\(3x=\frac{115}{21}\)                \(3x=\frac{95}{21}\)                         \(x=\frac{25}{16}\)

\(x=\frac{115}{63}\)                  \(x=\frac{95}{63}\)                             Vậy x = \(\frac{25}{16}\)

                      Vậy x \(\in\left\{\frac{115}{63};\frac{95}{63}\right\}\)

câu 1 

=> x+1/2+x+1/3+x+1/4-x-1/5-x-1/6=0

=> (x+x+x-x-x)+(1/2+1/3+1/4-1/5-1/6)=0

=> x+43/60=0

=> x = -43/60

câu dưới làm tương tự bạn nhé!