Decreasing then increasing, y goes down then y goes back up
<span>ΔABC, ΔDEF, and ΔGHI
</span>
I think all triangles are congruent. 2 sides and 1 angle of each triangle is has the same measure. Making these triangles congruent in SAS theorem.
Answer:

Step-by-step explanation:
The model shows that there are 40 tiles which were divided into 4 per group. This results into 10 groups. That is:

Therefore, the expression modeled by the arrangement of the tiles is 
It would be 9-6=3 and 9+6=17 hope this help