Algebra I All-in-One For Dummies. Mary Jane Sterling
Чтение книги онлайн.

Читать онлайн книгу Algebra I All-in-One For Dummies - Mary Jane Sterling страница 36

Название: Algebra I All-in-One For Dummies

Автор: Mary Jane Sterling

Издательство: John Wiley & Sons Limited

Жанр: Математика

Серия:

isbn: 9781119843061

isbn:

СКАЧАТЬ alt="math"/>

      13 47. Regroup so that the first two numbers are together. Their sum is 0!

math

      14 5. Regroup so that the second two numbers are together.

math

      15 70. Regroup so that the first two numbers are together. The fraction reduces to make the multiplication easier.

math

      16 110. Regroup so that the second two numbers are together. The multiplication is simple!

math

      17 5. Switch the order of the second and third numbers.

math

      18 470. Switch the order of the second and third numbers.

math

      19 78. Switch the order of the second and third numbers.

math

      20 8. Switch the order of the second and third numbers.

math

      21 560. There’s a lot of switching that goes on here to make the problem easier. Your goal is to be able to multiply fractions times numbers that will eliminate their denominators. In this particular problem, I’m bringing the math up next to the 16 and the math up next to the 18.

math

      Then I group, reduce, multiply, and find the product of the three “nice” numbers!

math

      22 –11 and math. The sum of 11 and –11 is 0; the product of 11 and math is 1.

      23 mathand –3. The sum of math and math is 0; the product of math and –3 is 1.

      24 math and math. The sum of math and math is 0; the product of math and math is 1.

      25 1 and –1. The sum of –1 and 1 is 0; the product of –1 and –1 is 1. The number is its own multiplicative inverse.

math

      You’ll see more on working with fractions in Chapter 4.

      27 math and math. The additive inverse is just the positive version of the same number. To write the multiplicative inverse, you change the mixed number to an improper fraction and just flip it:

math

      There’s a full coverage of fractions in Chapter 4.

      28 Use 8. The additive inverse of –8 is 8. If you add 8 to the expression, you have math. Use the associative property to group the –8 and 8 together: math. The sum of a number and its additive inverse is 0, so the expression becomes math. Because 0 is the additive identity, math.

      29 Use –6. The additive inverse of 6 is –6. If you add –6 to the expression, you have math. Use the associative property to group the 6 and –6 together: math. The sum of a number and its additive inverse is 0, so the expression becomes 0 – 3x. Because 0 is the additive identity, math.

      30 Use math. The multiplicative inverse of –7 is math. If you multiply the expression by СКАЧАТЬ