I need help, also I need to write a written response to explain the number of hours Enrique studies is proportional to the number of hours Veronica studies

Can someone explain the elimination method to me for this problem?

Maria solved an equation as shown below. what is the solution to maria’s equation?

Plzz ! if you were constructing a triangular frame, and you had wood in the length of 4 inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood? yes or no? = explain your mathematical thinking/show your work: