 I can solve equations by using the Addition and Subtraction Properties of Equality.

Addition Property of Equality  If you add the same number to each side of an equation, the two sides remain equal.  a + c = b + c if a = b

Example x - 7 = - 4 x – 7 = = x + 0 = 3 x = 3

Let’s Do It 13.9 = n – 9.7 Y – 6.4 =

Subtraction Property of Equality  If you subtract the same number from each side of an equation, the two sides remain equal.  a – c = b –c if a = b

Example n + 4 = = n = 5

Let’s Do It 23 = y a =

Pets  Keisha feeds her dog 2/3 cup of food in the morning. She feeds the dog a total of 1 ½ cup of food every day. Write an addition equation to find how much food she gives the dog the rest of the day. Solve the problem. 2/3 + x = 1 ½ 5/6 cup

Sports  Damon scored 13 points more than Wes and 9 points less than Ross. Ross scored 97. Write and solve equations to find the scores of Damon and Wes. 97 – 9 = d d – 13 = w Damon scored 88 points Wes scored 75 points