Читать книгу Algebra I All-in-One For Dummies - Mary Jane Sterling, Mary Sterling Jane - Страница 67

In mathematics, the inverse of a number is tied to a specific operation.

The additive inverse of the number 5 is –5; the additive inverse of the number is . When you add a number and its additive inverse together, you always get 0, the additive identity. Every real number has an additive inverse, even the number 0. The number 0 is its own additive inverse. And all real numbers (except 0) and their inverses have opposite signs; the number 0 is neither positive nor negative, so there is no sign.

The multiplicative inverse of the number 5 is ; the multiplicative inverse of the number is –3. When you multiply a number and its multiplicative inverse together, you always get 1, the multiplicative identity. Every real number except the number 0 has a multiplicative inverse. A number and its multiplicative inverse are always the same sign.

Q. Find the additive and multiplicative inverses of the number –14.

A. The additive inverse is 14, because . The multiplicative inverse of –14 is , because .

Q. Find the additive and multiplicative inverses of the number .

A. The additive inverse is , because . The multiplicative inverse of is , because .

Find the additive and multiplicative inverses of the given number.

22 11

23

24

25 –1

26 4.5

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