Sections 2-1, 2-2, 2-3

Notes Identity Property of Addition: x + 0 = x ex: = 5 The opposite of a number is its additive inverse: x + -x = 0 ex: = 0

Reminder When adding or subtracting fractions you need a common denominator Example:

Matrices

Tips When subtracting numbers turn the subtraction into adding a negative. 2 – 6 = = -4 Also it sometimes helps picturing a number line

Notes Identity Property of Multiplication 1n = n ex: 1 x 5 = 5 Multiplication Property of Zero 0n = 0 ex: 0 x 5 = 0 Multiplication Property of -1 -1n = -n ex: -1 x 5 = -5

Notes

The multiplicative inverse of x is Example: The multiplicative inverse of is The multiplicative inverse is the number that when multiplied by the original number equals 1.