11 7 Dividing Integers Learn to divide integers

11 -7 Dividing Integers Learn to divide integers. Course 1

11 -7 Dividing Integers Multiplication and division are inverse operations. To solve a division problem, think of the related multiplication. Remember! To find the mean of a list of numbers: 1. Add all the numbers together. 2. Divide by how many numbers are in the list. Course 1

11 -7 Dividing Integers Additional Example 1: Dividing Integers Find each quotient. A. – 30 ÷ 6 Think: What number times 6 equals – 30? – 5 • 6 = – 30, so – 30 ÷ 6 = – 5. B. – 42 ÷ (– 7) Think: What number times – 7 equals – 42? 6 Course 1 • (– 7) = – 42, so – 42 ÷ (– 7) = 6.

11 -7 Dividing Integers Check It Out: Example 1 Find each quotient. A. – 15 ÷ 5 Think: What number times 5 equals – 15? – 3 • 5 = – 15, so – 15 ÷ 5 = – 3. B. – 36 ÷ (– 6) Think: What number times -6 equals – 36? 6 Course 1 • (– 6) = – 36, so – 36 ÷ (– 6) = 6.

11 -7 Dividing Integers Because division is the inverse of multiplication, the rules for dividing integers are the same as the rules for multiplying integers. Dividing Integers If the signs are the same, the product is positive. 24 ÷ 3 = 8 – 6 ÷ (– 3) = 2 If the signs are different, the quotient is negative. – 20 ÷ 5 = – 4 72 ÷ (– 8) = – 9 Zero divided by any integer equals 0. 0 0 __ __ =0 =0 – 11 14 You cannot divide any integer by 0. Course 1

11 -7 Dividing Integers Additional Example 2 A: Evaluating Integer Expressions d for each value of d. Evaluate __ 4 d = 16 d __ 4 16 __ = 16 ÷ 4 4 =4 Course 1 Write the expression. Substitute 16 for d. The signs are the same, so the answer is positive.

11 -7 Dividing Integers Additional Example 2 B: Evaluating Integer Expressions d for each value of d. Evaluate __ 4 d = – 24 d __ 4 Write the expression. -24 ___ = – 24 ÷ 4 Substitute – 24 for d. 4 = – 6 The signs are different, so the answer is negative. Course 1

11 -7 Dividing Integers Additional Example 2 C: Evaluating Integer Expressions d for each value of d. Evaluate __ 4 d = – 12 d __ 4 Write the expression. -12 ___ = – 12 ÷ 4 Substitute – 12 for d. 4 = – 3 The signs are different, so the answer is negative. Course 1

11 -7 Dividing Integers Check It Out: Example 2 A c Evaluate __ for each value of c. 3 c = – 15 c __ 3 Write the expression. -15 ___ = – 15 ÷ 3 Substitute – 15 for c. 3 = – 5 Course 1 The signs are different, so the answer is negative.

11 -7 Dividing Integers Check It Out: Example 2 B c Evaluate __ for each value of c. 3 c = 12 c __ 3 12 ___ = 12 ÷ 3 3 =4 Course 1 Write the expression. Substitute 12 for c. The signs are the same, so the answer is positive.

11 -7 Dividing Integers Check It Out: Example 2 C c Evaluate __ for each value of c. 3 c = 27 c __ 3 27 __ = 27 ÷ 3 3 =9 Course 1 Write the expression. Substitute 27 for c. The signs are the same, so the answer is positive.

11 -7 Dividing Integers Insert Lesson Title Here Lesson Quiz Find each quotient. 1. 18 ÷ (– 3) – 6 2. – 36 ÷ (– 6) 6 3. – 64 ÷ (– 8) 8 4. – 45 ÷ 3 x __ Evaluate 4 for each value of x. – 15 5. x = – 12 – 3 5 6. x = 20 7. Carmen’s mom has $3, 200 in her bank account. If she uses the money to make monthly rent payments of $375, how many whole payments can she make? 8 Course 1