Question

Use properties of addition and subtraction to evaluate the expression.

−42−29−28

Enter your answer in the box.

Answer 1

- 42 -29 - 28 =( -42-28) -29 = - 70 - 29= -99

Answer 2

-99

Explanation:

The properties of addition are

1. Commutative property states that the sum of two number is the same regardless the order of the addends.
2. Associative property states that the grouping of the addends is the same regardless the grouping order of three or more numbers being added.
3. Distributive property states that the sum of two number which multiplies a third number is equal to the sum of the product of each addends with that third number.

Now, in the given expression
`-42-29-28`

We have three negative numbers, so if we extract the common sign, we would have

`-(42+29+28)`

This extraction is possible because of the distributive property, we are applying it backwards to group all number.

Now, we sum all numbers grouped

`-(99)`

Then, we multiply the negative sign with the number inside the parenthesis

`-(99)=-99`

Therefore, the evaluation of the expression gives
`-99`

`-42-29-28=-99`