Karina bought 8 bagels and used a gift certificate for $4. Her total cost is represented by the expression 8b - 4, where b is the cost of a bagel. What is an equivalent expression?

An equivalent expression = 8b + (-4)

Step-by-step explanation:

In Mathematics, numbers exhibit or are guided by certain properties that they can show.

Some of those of properties are:

a) Commutative property where:

a + b = b + a

b) Associative property

a + (b + c) = (a + b) + c

c) Additive inverse property

a - b = a + ( - b)

For the question above, we are told that the total cost of what Karen bough is represented by the expression 8b - 4. We are asked find the equivalent expression.

An equivalent expression is defined as an expression that has the exact value for all the values obtained from the variable.

Hence, using the Additive inverse property

a - b = a + ( - b)

The equivalent expression for 8b - 4 = 8b + (-4)