Identity and conditional equations are means by which numbers associate with each other. If an equation is true for each value of the variable, the equation is called the identity equation. It is often called I or E (the E comes from the German unit or « unit »). For example, 3x = 3x is an identity equation because x will always be the same number. Null is the identity element to add because a number added to 0 does not change the value of one of the other numbers in the operation (or x + 0 = x). The number 1 is the identity element of the multiplication because any number in an operation multiplied by 1 does not change the value of this number. Multiple identity is often written as x × 1 = x. This is a web preview of the « The Handy Math Answer Book » app. Many features only work on your mobile device.

If you like what you see, we hope you`re considering buying. Get the application If an equation is incorrect for at least one value, it is called a conditional equation. For example, 6x = 12 is conditional because it is wrong if x = 3 (and any number other than 2). In other words, if at least one value can be found in which the equation is false (or the right side is not equal to the left side), the equation is called a conditional equation. .