In his book 'Kitab al-Jabr wal-Muqabala', Al-Khwarizmi:
Q1. In his book 'Kitab al-Jabr wal-Muqabala', Al-Khwarizmi:
Answer: Solved linear and quadratic equations
Explanation: In "Kitab al-Jabr wal-Muqabala" (c. 820 AD), Al-Khwarizmi systematically solved linear and quadratic equations, giving algebra its name.