(present value-original value)/original value x 100%.

Suppose the original number is a and the present number is b, if a >；; B, reduction percentage =[(a-b)/a]* 100%.

The definition of decline is the degree of reduction. Refers to the price of goods.

Formulas (mathematical terms and words with other meaning):

1, a general format, is expressed by mathematical symbols. The formula of a certain relationship (such as law or theorem) between various quantities can generally be applied to the ways and means of similar things. ?

2, formula, in mathematics, physics, chemistry, biology and other natural sciences, using mathematical symbols to express the relationship between several quantities. It is universal and applicable to all similar problems. In mathematical logic, a formula is a formal grammatical object to express a proposition, but the proposition may depend on the free variable value of the formula.

The precise definition of a formula depends on the specific formal logic involved, but there is a very typical definition (for first-order logic): the formula is defined relative to a specific language; That is, a set of constant symbols, function symbols and relational symbols, in which each function and relational symbol has an arity to indicate the number of parameters it accepts.