Saggar kiln debris. Modern saggars are made of alumina ceramic, cordierite ceramic, mullite ceramic silicon carbide and in special cases from zirconia. By far the largest number of UK pottery manufacturers were based in and around Stoke-on-Trent in a region known as The Potteries. Their businesses, locally known as potbanks, fired their wares in distinctive bottle ovens. At the turn of the twentieth century over 4,000 of these were in use, although by 2014 only 47 survive, all of which are no longer in production but are listed buildings. The saggars were used for the biscuit and the glost firing. They
Like terms The like terms in this expression are the terms that can be grouped together by having exactly the same set of unknown factors. Here, the sets of unknown factors are formula_15 formula_16 and formula_17. By the rule in the first example, all terms with the same set of unknown factors, that is, all like terms, may be combined by adding or subtracting their coefficients, while maintaining the unknown factors. Thus, the expression becomes formula_18 The expression is considered simplified when all like terms have been combined, and all terms present are unlike. In this case, all terms now have different