Question

Emma said that when you multiply three negative decimals, the product will be positive. Use three numbers to answer the question:-2.5, -3.8, -2.7, 4.5Part A: Emma's statement always true, sometimes true, or always false? Write two equations to support your answerPart B: Write a rule for multiplying three negative decimals.Part C: Emma changed her statement to say that when you multiply two negative decimals and a positive decimal, the product will be positive. Is Emma new statement always true, sometimes true, or always false? Write two equations to support your answer.

Answer 1

The 3 negative numbers that would be used are - 2.5, - 3.8, - 2.7

Part A. Emma's statement is false. This is because when a negative number is multiplied by another negative number, the result is positve. When this positive result is multiplied by a negative number, the result would be negative

- 2.5 * - 3.8 = 9.5

- 2.7 * 9.5 = - 25.65

Part B

The rules for multiplying 3 negative decimals are

1) 2 negative values will always give a positive value

2) The other negative value multiplied by the positve value will give a negative value.

Part C

When 2 negative decimals are multiplied, the product is positive. Thus, Emma's statement is always true.

- 2.5 * - 3.8 = 9.5

- 2.5 * - 2.7 = 6.75