What is the solution to the equation 4x-2=18

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:

Find the value of x. also give me an explanation so i can complete it to other questions as well, : )

Ahousekeeper mixed 5 gallons of blue paint with every 9 gallon of yellow paint in order to make a green paint which ratio of gallon of blue paint to gallon of yellow paint will make the same shade of green paint