3x^2-18=0

=>x^2=6

=>x=\(+-\sqrt{6}\)

13/12>12/12=1

=>13/12>1`

=>x^2+x^2+...+x^2+1+2+3+...+100=15050

=>100*x^2+(100+1)*100/2=15050

=>100x^2+5050=15050

=>100x^2=10000

=>x^2=100

=>x=10;x=-10

.

325+196+175+20

=325+175+196+20

=500+216

=716

số tự nhiên mấy chữ số ạ

n và m có mấy chữ so ạ 

3/1*5+3/5*9+...+3/2017*2021

=3/4*(4/1.5+4/5.9+...+4/2017*2021)

3/4(1-1/5+1/5-1/9+...+1/2017-1/2021)

=3/4*(2020/2021)

=1515/2021

\(\dfrac{\sqrt{2}+\sqrt{3}+\sqrt{6}+\sqrt{8}+\sqrt{16}}{\sqrt{2}+\sqrt{3}+2}\)

\(\dfrac{\sqrt{2}+\sqrt{3}+\sqrt{6}+\sqrt{8}+4}{\sqrt{2}+\sqrt{3}+2}\)

\(\dfrac{\sqrt{2}+\sqrt{3}+2+\sqrt{6}+\sqrt{8}+2}{\sqrt{2}+\sqrt{3}+2}\)

\(\dfrac{\sqrt{2}+\sqrt{3}+2+\sqrt{2}\left(\sqrt{2}+\sqrt{3}+2\right)}{\sqrt{2}+\sqrt{3}+2}\)

`=`\(\sqrt{2}+1\)

-4^2-5/3:x=-1/2^3

16-5/3x=-1/8

=>-5/3x=-129/8

x=387/40