<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>数学方程式</title> </head> <body> <h3 style="color: red;text-align: center;font-size: 24px;">数学方程式</h3> <hr width="80%" size="2" color="blue"/> <p align="center">2x<sup>2</sup>+3x=9</p> <p align="center">x<sub>1</sub>+x<sub>2</sub>=10</p> </body> </html>