Welshman, Robert Recorde, born in Tenby, is credited in 1557 with introducing algebra to England, and the = sign. However some continued to use the ae and oe ( short for aequalis), and vertical parallel lines until the 1700.s.
In The One of Wit of 1557, Recorde stated, [in the language of the time]: ‘To avoide the tedious repetition of these woordes: is equall to : I will settle as I doe offer in woorke use, a paire of paralleles, or gemowe [twin] lines of one lengthe =, because noe 2 thynges, can be moare equalle….’ (sic).
Recorde had a chequered career which landed him in prison, leaving him feeling, no doubt, his future was in jeopardy.
For it was Today in 1558 that the physician and mathematician made a will inside King’s Bench Prison, Southwark, having been put there for being unable to pay the debt for libel to William Herbert, 1st Earl of Pembroke. He died soon afterwards.
Then Recorde was made Surveyor of Mines and Monies in Ireland, but failing to make a profit was dismissed in 1553.
He wrote many books including the ‘Declaration of the Profit of Aritmeticke’ (sic), written to try to improve knowledge of basic arithmetic, in the preface writing about the poor state of learning in England. Nothing changes!
He also says, ‘how the learned are made fun of by the uneducated…it was a great cause of lament….when learned men…takes pain to do things for the aid of the unlearned. But derided and scorned and so utterly discouraged to take in hand any like enterprise again’.
Al-jabr (algebra) comes from Arabic mathematicians and which term, ‘refers to: reduction and balancing (transposition) of subtracted terms to the other side of the equation’.
In other terms, cancellation of like terms (constant terms) on opposite sides of the equation.
Abstract algebra should not be confused with manipulation of formulae as happens widely in schools, but what Recorde did in his books was bridge the difference between theory and application. However despite all his best efforts, for most today, Algebra is still a closed book.