Could someone please answer this I will give a brainless if answer correctly and explained

SSS

Step-by-step explanation:

The SSS theorem is the side-side-side theorem. Basically, since all three sides from one triangle is congruent to the corresponding sides of the other triangle, then the triangles have to be congruent. There are other theorems such as the SAS theorem (side-angle-side), but since the question only give us the fact that the sides are congruent, its SSS. Sorry, I hope this is good enough. XD

answ9x x 3=

step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.