Choose which expression doesn’t belong? State your reasoning.

Step-by-step explanation:

This warm-up prompts students to carefully analyze and compare quadratic expressions. In making comparisons, students need to look for common structure and have a reason to use language precisely (MP7, MP6). The activity also enables the teacher to hear the terminology students know and how they talk about characteristics of the different forms of expressions.

As students discuss in groups, listen for rationales that are based on the structure of the expressions. Select those students or groups to share their thinking during class discussion.

Launch

Arrange students in groups of 2–4. Display the expressions for all to see. Give students 1 minute of quiet think time and then time to share their thinking with their small group. In their small groups, ask each student to share their reasoning about why a particular item does not belong, and together find at least one reason each item doesn't belong.

Student Facing

Which one doesn’t belong?

A.

B.

C.

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!