text: can the rules of  mathematical formulas change? basic maths:  seems to me to have have one rule for some and others for calculus. i am shore that you transfer x onto the other side by dividing, or multiplying (depending) yet here in calc. they subtract x, does this make logical sense, or do people change the rules, or does things like this work out either way? thanks. the rules of math are always consistent.  i'm not really sure what you're asking about x, but different problems are solved in different ways.  in algebra, adding or subtracting x is usually enough to get your solution, while calculus often involves multiplying by x or dividing out powers of x.  more complicated math requires more complicated formulae, but that doesn't mean that the rules of the more basic formulae have been changed.